🐛 fix(sql): 适配多数据源 SQL 方言生成

- 表设计 DDL 按 Oracle/Dameng、SQL Server、PG-family、SQLite/DuckDB、ClickHouse/TDengine 分支生成 - 新增统一 SQL 方言工具，驱动字段类型候选和 SQL 自动补全 - 修复 Oracle/Dameng DATE/TIMESTAMP 删除条件字面量 - 补充多方言 DDL、补全和 Oracle 删除回归测试 Refs #402 Refs #409
2026-07-28 01:09:17 +08:00 · 2026-04-26 17:14:07 +08:00
parent f16e2f15c2
commit df4fcab90b
9 changed files with 1497 additions and 163 deletions
--- a/frontend/src/components/tableDesignerSchemaSql.ts
+++ b/frontend/src/components/tableDesignerSchemaSql.ts
@@ -1,3 +1,16 @@
+import {
+  isBacktickIdentifierDialect,
+  isMysqlFamilyDialect,
+  isOracleLikeDialect,
+  isPgLikeDialect,
+  isSqlServerDialect,
+  quoteSqlIdentifierPart,
+  quoteSqlIdentifierPath,
+  resolveSqlDialect,
+  unquoteSqlIdentifierPart,
+  unquoteSqlIdentifierPath,
+} from '../utils/sqlDialect';
+
 export interface EditableColumnSnapshot {
  _key: string;
  name: string;
@@ -17,21 +30,17 @@ export interface BuildAlterTablePreviewInput {
  columns: EditableColumnSnapshot[];
 }

-const escapeSqlString = (value: string) => String(value || '').replace(/'/g, "''");
-const escapeBacktickIdentifier = (value: string) => String(value || '').replace(/`/g, '``');
-const escapeDoubleQuoteIdentifier = (value: string) => String(value || '').replace(/"/g, '""');
+export interface BuildCreateTablePreviewInput {
+  dbType: string;
+  tableName: string;
+  columns: EditableColumnSnapshot[];
+  charset?: string;
+  collation?: string;
+}

-const stripIdentifierQuotes = (part: string): string => {
-  const text = String(part || '').trim();
-  if (!text) return '';
-  if ((text.startsWith('`') && text.endsWith('`')) || (text.startsWith('"') && text.endsWith('"'))) {
-    return text.slice(1, -1).trim();
-  }
-  if (text.startsWith('[') && text.endsWith(']')) {
-    return text.slice(1, -1).replace(/]]/g, ']').trim();
-  }
-  return text;
-};
+const escapeSqlString = (value: string) => String(value || '').replace(/'/g, "''");
+
+const stripIdentifierQuotes = unquoteSqlIdentifierPart;

 const splitQualifiedName = (qualifiedName: string): { schemaName: string; objectName: string } => {
  const raw = String(qualifiedName || '').trim();
@@ -44,117 +53,158 @@ const splitQualifiedName = (qualifiedName: string): { schemaName: string; object
  };
 };

-const isMysqlLikeDialect = (dbType: string): boolean => dbType === 'mysql';
-const isPgLikeDialect = (dbType: string): boolean =>
-  dbType === 'postgres' || dbType === 'kingbase' || dbType === 'highgo' || dbType === 'vastbase';
+const quoteIdentifierPart = (part: string, dbType: string): string => quoteSqlIdentifierPart(dbType, part);

-const needsPgLikeQuote = (ident: string): boolean => !/^[a-z_][a-z0-9_]*$/.test(ident);
+const quoteIdentifierPath = (path: string, dbType: string): string => quoteSqlIdentifierPath(dbType, path);

-const quoteIdentifierPart = (part: string, dbType: string): string => {
-  const ident = stripIdentifierQuotes(part);
-  if (!ident) return '';
-  if (isMysqlLikeDialect(dbType)) {
-    return `\`${escapeBacktickIdentifier(ident)}\``;
-  }
-  if (isPgLikeDialect(dbType)) {
-    if (!needsPgLikeQuote(ident)) {
-      return ident;
-    }
-    return `"${escapeDoubleQuoteIdentifier(ident)}"`;
-  }
-  return ident;
+const normalizeDefaultText = (value: unknown): string => String(value ?? '').trim();
+
+const isKnownDefaultExpression = (trimmed: string): boolean => {
+  if (!trimmed) return false;
+  if (/^N?'.*'$/i.test(trimmed)) return true;
+  if (/^-?\d+(\.\d+)?$/.test(trimmed)) return true;
+  if (/^(true|false|null)$/i.test(trimmed)) return true;
+  if (/^(current_timestamp|current_date|current_time|localtimestamp|sysdate|systimestamp)$/i.test(trimmed)) return true;
+  if (/^(now|uuid|newid|sysdatetime)\s*\(\s*\)$/i.test(trimmed)) return true;
+  if (/^nextval\s*\(/i.test(trimmed) || /::/.test(trimmed)) return true;
+  return false;
 };

-const quoteIdentifierPath = (path: string, dbType: string): string =>
-  String(path || '')
-    .trim()
-    .split('.')
-    .map((part) => stripIdentifierQuotes(part))
-    .filter(Boolean)
-    .map((part) => quoteIdentifierPart(part, dbType))
-    .join('.');
-
-const formatPgLikeDefault = (value: string): string => {
-  const trimmed = String(value || '').trim();
+const formatDefaultExpression = (value: unknown, dbType: string): string => {
+  const trimmed = normalizeDefaultText(value);
  if (!trimmed) return '';
-  if (/^'.*'$/.test(trimmed)) return trimmed;
-  if (/^-?\d+(\.\d+)?$/.test(trimmed)) return trimmed;
-  if (/^(true|false|null)$/i.test(trimmed)) return trimmed.toUpperCase() === 'NULL' ? 'NULL' : trimmed.toUpperCase();
-  if (/^(current_timestamp|current_date|current_time)$/i.test(trimmed)) return trimmed.toUpperCase();
-  if (/^nextval\s*\(/i.test(trimmed) || /::/.test(trimmed)) return trimmed;
-  return `'${escapeSqlString(trimmed)}'`;
+  if (isKnownDefaultExpression(trimmed)) {
+    if (/^(true|false|null)$/i.test(trimmed)) return trimmed.toUpperCase();
+    if (/^(current_timestamp|current_date|current_time|localtimestamp|sysdate|systimestamp)$/i.test(trimmed)) {
+      return trimmed.toUpperCase();
+    }
+    return trimmed;
+  }
+  const prefix = isSqlServerDialect(dbType) ? 'N' : '';
+  return `${prefix}'${escapeSqlString(trimmed)}'`;
 };

-const buildMySqlColumnDefinition = (column: EditableColumnSnapshot): string => {
-  let extra = String(column.extra || '');
+const buildDefaultSql = (value: unknown, dbType: string): string => {
+  const defaultValue = normalizeDefaultText(value);
+  if (!defaultValue) return '';
+  return `DEFAULT ${formatDefaultExpression(defaultValue, dbType)}`;
+};
+
+const definitionChanged = (curr: EditableColumnSnapshot, orig: EditableColumnSnapshot): boolean => (
+  curr.type !== orig.type ||
+  curr.nullable !== orig.nullable ||
+  normalizeDefaultText(curr.default) !== normalizeDefaultText(orig.default) ||
+  (curr.comment || '') !== (orig.comment || '') ||
+  Boolean(curr.isAutoIncrement) !== Boolean(orig.isAutoIncrement)
+);
+
+const physicalDefinitionChanged = (curr: EditableColumnSnapshot, orig: EditableColumnSnapshot): boolean => (
+  curr.type !== orig.type ||
+  curr.nullable !== orig.nullable ||
+  normalizeDefaultText(curr.default) !== normalizeDefaultText(orig.default) ||
+  Boolean(curr.isAutoIncrement) !== Boolean(orig.isAutoIncrement)
+);
+
+const buildMySqlColumnDefinition = (column: EditableColumnSnapshot, dbType: string): string => {
+  let extra = String(column.extra || '').trim();
  if (column.isAutoIncrement) {
    if (!extra.toLowerCase().includes('auto_increment')) {
-      extra += ' AUTO_INCREMENT';
+      extra = `${extra} AUTO_INCREMENT`.trim();
    }
  } else {
    extra = extra.replace(/auto_increment/gi, '').trim();
  }
-  const defaultSql = column.default ? `DEFAULT '${escapeSqlString(String(column.default))}'` : '';
-  return `${quoteIdentifierPart(column.name, 'mysql')} ${column.type} ${column.nullable === 'NO' ? 'NOT NULL' : 'NULL'} ${defaultSql} ${extra} COMMENT '${escapeSqlString(column.comment || '')}'`.replace(/\s+/g, ' ').trim();
+  const defaultSql = buildDefaultSql(column.default, dbType);
+  return [
+    quoteIdentifierPart(column.name, dbType),
+    String(column.type || '').trim(),
+    column.nullable === 'NO' ? 'NOT NULL' : 'NULL',
+    defaultSql,
+    extra,
+    `COMMENT '${escapeSqlString(column.comment || '')}'`,
+  ].filter(Boolean).join(' ').replace(/\s+/g, ' ').trim();
 };

-const buildPgLikeColumnDefinition = (column: EditableColumnSnapshot): string => {
-  const parts = [quoteIdentifierPart(column.name, 'postgres'), String(column.type || '').trim()];
-  const defaultValue = String(column.default || '').trim();
-  if (defaultValue) {
-    parts.push(`DEFAULT ${formatPgLikeDefault(defaultValue)}`);
+const buildStandardColumnDefinition = (
+  column: EditableColumnSnapshot,
+  dbType: string,
+  options: { includeNull?: boolean; includeIdentity?: boolean } = {},
+): string => {
+  const parts = [quoteIdentifierPart(column.name, dbType), String(column.type || '').trim()];
+  if (options.includeIdentity && column.isAutoIncrement) {
+    if (isSqlServerDialect(dbType)) {
+      parts.push('IDENTITY(1,1)');
+    } else if (isOracleLikeDialect(dbType)) {
+      parts.push('GENERATED BY DEFAULT AS IDENTITY');
+    }
  }
+  const defaultSql = buildDefaultSql(column.default, dbType);
+  if (defaultSql) parts.push(defaultSql);
  if (column.nullable === 'NO') {
    parts.push('NOT NULL');
+  } else if (options.includeNull) {
+    parts.push('NULL');
  }
+  return parts.filter(Boolean).join(' ').trim();
+};
+
+const buildPgLikeColumnDefinition = (column: EditableColumnSnapshot, dbType: string): string => {
+  const parts = [quoteIdentifierPart(column.name, dbType), String(column.type || '').trim()];
+  const defaultSql = buildDefaultSql(column.default, dbType);
+  if (defaultSql) parts.push(defaultSql);
+  if (column.nullable === 'NO') parts.push('NOT NULL');
  return parts.join(' ').trim();
 };

-const buildPgLikeCommentSql = (tableRef: string, columnName: string, comment: string): string => {
-  const columnRef = `${tableRef}.${quoteIdentifierPart(columnName, 'postgres')}`;
+const buildColumnCommentSql = (tableRef: string, columnName: string, comment: string, dbType: string): string => {
+  const columnRef = `${tableRef}.${quoteIdentifierPart(columnName, dbType)}`;
  const trimmed = String(comment || '').trim();
-  if (!trimmed) {
+  if (!trimmed && isPgLikeDialect(dbType)) {
    return `COMMENT ON COLUMN ${columnRef} IS NULL;`;
  }
  return `COMMENT ON COLUMN ${columnRef} IS '${escapeSqlString(trimmed)}';`;
 };

-const buildMySqlAlterPreviewSql = (input: BuildAlterTablePreviewInput): string => {
-  const tableName = quoteIdentifierPath(input.tableName, 'mysql');
+const buildSqlServerColumnCommentSql = (
+  tableName: string,
+  columnName: string,
+  comment: string,
+): string => {
+  const { schemaName, objectName } = splitQualifiedName(tableName);
+  const schema = escapeSqlString(schemaName || 'dbo');
+  const table = escapeSqlString(objectName || tableName);
+  const column = escapeSqlString(columnName);
+  const value = escapeSqlString(comment || '');
+  return `IF EXISTS (SELECT 1 FROM sys.extended_properties ep JOIN sys.tables t ON ep.major_id = t.object_id JOIN sys.schemas s ON t.schema_id = s.schema_id JOIN sys.columns c ON ep.major_id = c.object_id AND ep.minor_id = c.column_id WHERE ep.name = N'MS_Description' AND s.name = N'${schema}' AND t.name = N'${table}' AND c.name = N'${column}') BEGIN EXEC sp_updateextendedproperty @name = N'MS_Description', @value = N'${value}', @level0type = N'SCHEMA', @level0name = N'${schema}', @level1type = N'TABLE', @level1name = N'${table}', @level2type = N'COLUMN', @level2name = N'${column}' END ELSE BEGIN EXEC sp_addextendedproperty @name = N'MS_Description', @value = N'${value}', @level0type = N'SCHEMA', @level0name = N'${schema}', @level1type = N'TABLE', @level1name = N'${table}', @level2type = N'COLUMN', @level2name = N'${column}' END;`;
+};
+
+const buildMySqlAlterPreviewSql = (input: BuildAlterTablePreviewInput, dbType: string): string => {
+  const tableName = quoteIdentifierPath(input.tableName, dbType);
  const alters: string[] = [];

  input.originalColumns.forEach((orig) => {
    if (!input.columns.find((col) => col._key === orig._key)) {
-      alters.push(`DROP COLUMN ${quoteIdentifierPart(orig.name, 'mysql')}`);
+      alters.push(`DROP COLUMN ${quoteIdentifierPart(orig.name, dbType)}`);
    }
  });

  input.columns.forEach((curr, index) => {
    const orig = input.originalColumns.find((col) => col._key === curr._key);
    const prevCol = index > 0 ? input.columns[index - 1] : null;
-    const positionSql = prevCol ? `AFTER ${quoteIdentifierPart(prevCol.name, 'mysql')}` : 'FIRST';
-    const colDef = buildMySqlColumnDefinition(curr);
+    const positionSql = prevCol ? `AFTER ${quoteIdentifierPart(prevCol.name, dbType)}` : 'FIRST';
+    const colDef = buildMySqlColumnDefinition(curr, dbType);

    if (!orig) {
      alters.push(`ADD COLUMN ${colDef} ${positionSql}`.trim());
      return;
    }

-    const definitionChanged =
-      curr.type !== orig.type ||
-      curr.nullable !== orig.nullable ||
-      curr.default !== orig.default ||
-      (curr.comment || '') !== (orig.comment || '') ||
-      Boolean(curr.isAutoIncrement) !== Boolean(orig.isAutoIncrement);
-
    if (curr.name !== orig.name) {
-      alters.push(
-        `CHANGE COLUMN ${quoteIdentifierPart(orig.name, 'mysql')} ${colDef} ${positionSql}`.trim(),
-      );
+      alters.push(`CHANGE COLUMN ${quoteIdentifierPart(orig.name, dbType)} ${colDef} ${positionSql}`.trim());
      return;
    }

-    if (definitionChanged) {
+    if (definitionChanged(curr, orig)) {
      alters.push(`MODIFY COLUMN ${colDef} ${positionSql}`.trim());
    }
  });
@@ -163,74 +213,65 @@ const buildMySqlAlterPreviewSql = (input: BuildAlterTablePreviewInput): string =
  const newPKKeys = input.columns.filter((col) => col.key === 'PRI').map((col) => col._key);
  const keysChanged = origPKKeys.length !== newPKKeys.length || !origPKKeys.every((key) => newPKKeys.includes(key));
  if (keysChanged) {
-    if (origPKKeys.length > 0) {
-      alters.push('DROP PRIMARY KEY');
-    }
+    if (origPKKeys.length > 0) alters.push('DROP PRIMARY KEY');
    if (newPKKeys.length > 0) {
      const pkNames = input.columns
        .filter((col) => col.key === 'PRI')
-        .map((col) => quoteIdentifierPart(col.name, 'mysql'))
+        .map((col) => quoteIdentifierPart(col.name, dbType))
        .join(', ');
      alters.push(`ADD PRIMARY KEY (${pkNames})`);
    }
  }

-  if (alters.length === 0) {
-    return '';
-  }
-  return `ALTER TABLE ${tableName}\n${alters.join(',\n')};`;
+  return alters.length === 0 ? '' : `ALTER TABLE ${tableName}\n${alters.join(',\n')};`;
 };

-const buildPgLikeAlterPreviewSql = (input: BuildAlterTablePreviewInput): string => {
+const buildPgLikeAlterPreviewSql = (input: BuildAlterTablePreviewInput, dbType: string): string => {
  const tableParts = splitQualifiedName(input.tableName);
  const baseTableName = tableParts.objectName || stripIdentifierQuotes(input.tableName);
-  const tableRef = quoteIdentifierPath(input.tableName, 'postgres');
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
  const statements: string[] = [];

  input.originalColumns.forEach((orig) => {
    if (!input.columns.find((col) => col._key === orig._key)) {
-      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, 'postgres')};`);
+      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, dbType)};`);
    }
  });

  input.columns.forEach((curr) => {
    const orig = input.originalColumns.find((col) => col._key === curr._key);
    if (!orig) {
-      statements.push(`ALTER TABLE ${tableRef}\nADD COLUMN ${buildPgLikeColumnDefinition(curr)};`);
-      if (String(curr.comment || '').trim()) {
-        statements.push(buildPgLikeCommentSql(tableRef, curr.name, curr.comment || ''));
-      }
+      statements.push(`ALTER TABLE ${tableRef}\nADD COLUMN ${buildPgLikeColumnDefinition(curr, dbType)};`);
+      if (String(curr.comment || '').trim()) statements.push(buildColumnCommentSql(tableRef, curr.name, curr.comment || '', dbType));
      return;
    }

    let currentName = orig.name;
    if (curr.name !== orig.name) {
-      statements.push(`ALTER TABLE ${tableRef}\nRENAME COLUMN ${quoteIdentifierPart(orig.name, 'postgres')} TO ${quoteIdentifierPart(curr.name, 'postgres')};`);
+      statements.push(`ALTER TABLE ${tableRef}\nRENAME COLUMN ${quoteIdentifierPart(orig.name, dbType)} TO ${quoteIdentifierPart(curr.name, dbType)};`);
      currentName = curr.name;
    }

    if (curr.type !== orig.type) {
-      statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, 'postgres')} TYPE ${curr.type};`);
+      statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} TYPE ${curr.type};`);
    }

-    const currDefault = String(curr.default || '').trim();
-    const origDefault = String(orig.default || '').trim();
+    const currDefault = normalizeDefaultText(curr.default);
+    const origDefault = normalizeDefaultText(orig.default);
    if (currDefault !== origDefault) {
      if (currDefault) {
-        statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, 'postgres')} SET DEFAULT ${formatPgLikeDefault(currDefault)};`);
+        statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} SET DEFAULT ${formatDefaultExpression(currDefault, dbType)};`);
      } else {
-        statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, 'postgres')} DROP DEFAULT;`);
+        statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} DROP DEFAULT;`);
      }
    }

    if (curr.nullable !== orig.nullable) {
-      statements.push(
-        `ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, 'postgres')} ${curr.nullable === 'NO' ? 'SET NOT NULL' : 'DROP NOT NULL'};`,
-      );
+      statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} ${curr.nullable === 'NO' ? 'SET NOT NULL' : 'DROP NOT NULL'};`);
    }

    if ((curr.comment || '') !== (orig.comment || '')) {
-      statements.push(buildPgLikeCommentSql(tableRef, currentName, curr.comment || ''));
+      statements.push(buildColumnCommentSql(tableRef, currentName, curr.comment || '', dbType));
    }
  });

@@ -239,12 +280,12 @@ const buildPgLikeAlterPreviewSql = (input: BuildAlterTablePreviewInput): string
  const keysChanged = origPKKeys.length !== newPKKeys.length || !origPKKeys.every((key) => newPKKeys.includes(key));
  if (keysChanged) {
    if (origPKKeys.length > 0) {
-      statements.push(`ALTER TABLE ${tableRef}\nDROP CONSTRAINT IF EXISTS ${quoteIdentifierPart(`${baseTableName}_pkey`, 'postgres')};`);
+      statements.push(`ALTER TABLE ${tableRef}\nDROP CONSTRAINT IF EXISTS ${quoteIdentifierPart(`${baseTableName}_pkey`, dbType)};`);
    }
    if (newPKKeys.length > 0) {
      const pkNames = input.columns
        .filter((col) => col.key === 'PRI')
-        .map((col) => quoteIdentifierPart(col.name, 'postgres'))
+        .map((col) => quoteIdentifierPart(col.name, dbType))
        .join(', ');
      statements.push(`ALTER TABLE ${tableRef}\nADD PRIMARY KEY (${pkNames});`);
    }
@@ -253,13 +294,322 @@ const buildPgLikeAlterPreviewSql = (input: BuildAlterTablePreviewInput): string
  return statements.join('\n');
 };

-export const buildAlterTablePreviewSql = (input: BuildAlterTablePreviewInput): string => {
-  const dbType = String(input.dbType || '').trim().toLowerCase();
-  if (isPgLikeDialect(dbType)) {
-    return buildPgLikeAlterPreviewSql({ ...input, dbType });
+const buildOracleLikeAlterPreviewSql = (input: BuildAlterTablePreviewInput, dbType: string): string => {
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
+  const statements: string[] = [];
+
+  input.originalColumns.forEach((orig) => {
+    if (!input.columns.find((col) => col._key === orig._key)) {
+      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, dbType)};`);
+    }
+  });
+
+  input.columns.forEach((curr) => {
+    const orig = input.originalColumns.find((col) => col._key === curr._key);
+    if (!orig) {
+      statements.push(`ALTER TABLE ${tableRef}\nADD (${buildStandardColumnDefinition(curr, dbType, { includeIdentity: true })});`);
+      if (String(curr.comment || '').trim()) statements.push(buildColumnCommentSql(tableRef, curr.name, curr.comment || '', dbType));
+      return;
+    }
+
+    let currentName = orig.name;
+    if (curr.name !== orig.name) {
+      statements.push(`ALTER TABLE ${tableRef}\nRENAME COLUMN ${quoteIdentifierPart(orig.name, dbType)} TO ${quoteIdentifierPart(curr.name, dbType)};`);
+      currentName = curr.name;
+    }
+
+    if (physicalDefinitionChanged(curr, orig)) {
+      statements.push(`ALTER TABLE ${tableRef}\nMODIFY (${buildStandardColumnDefinition({ ...curr, name: currentName }, dbType, { includeIdentity: true })});`);
+    }
+
+    if ((curr.comment || '') !== (orig.comment || '')) {
+      statements.push(buildColumnCommentSql(tableRef, currentName, curr.comment || '', dbType));
+    }
+  });
+
+  const origPKKeys = input.originalColumns.filter((col) => col.key === 'PRI').map((col) => col._key);
+  const newPKKeys = input.columns.filter((col) => col.key === 'PRI').map((col) => col._key);
+  const keysChanged = origPKKeys.length !== newPKKeys.length || !origPKKeys.every((key) => newPKKeys.includes(key));
+  if (keysChanged) {
+    if (origPKKeys.length > 0) statements.push(`ALTER TABLE ${tableRef}\nDROP PRIMARY KEY;`);
+    if (newPKKeys.length > 0) {
+      const pkNames = input.columns.filter((col) => col.key === 'PRI').map((col) => quoteIdentifierPart(col.name, dbType)).join(', ');
+      statements.push(`ALTER TABLE ${tableRef}\nADD PRIMARY KEY (${pkNames});`);
+    }
  }
-  return buildMySqlAlterPreviewSql({ ...input, dbType });
+
+  return statements.join('\n');
+};
+
+const buildSqlServerDefaultDropBatch = (tableName: string, columnName: string): string => {
+  const { schemaName, objectName } = splitQualifiedName(tableName);
+  const schema = escapeSqlString(schemaName || 'dbo');
+  const table = escapeSqlString(objectName || tableName);
+  const column = escapeSqlString(columnName);
+  const tableRef = quoteIdentifierPath(`${schemaName || 'dbo'}.${objectName || tableName}`, 'sqlserver');
+  return `DECLARE @gonavi_df nvarchar(128); SELECT @gonavi_df = dc.name FROM sys.default_constraints dc JOIN sys.columns c ON dc.parent_object_id = c.object_id AND dc.parent_column_id = c.column_id JOIN sys.tables t ON c.object_id = t.object_id JOIN sys.schemas s ON t.schema_id = s.schema_id WHERE s.name = N'${schema}' AND t.name = N'${table}' AND c.name = N'${column}'; IF @gonavi_df IS NOT NULL EXEC(N'ALTER TABLE ${tableRef} DROP CONSTRAINT ' + QUOTENAME(@gonavi_df));`;
+};
+
+const buildSqlServerAlterPreviewSql = (input: BuildAlterTablePreviewInput): string => {
+  const dbType = 'sqlserver';
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
+  const statements: string[] = [];
+
+  input.originalColumns.forEach((orig) => {
+    if (!input.columns.find((col) => col._key === orig._key)) {
+      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, dbType)};`);
+    }
+  });
+
+  input.columns.forEach((curr) => {
+    const orig = input.originalColumns.find((col) => col._key === curr._key);
+    if (!orig) {
+      statements.push(`ALTER TABLE ${tableRef}\nADD ${buildStandardColumnDefinition(curr, dbType, { includeNull: true, includeIdentity: true })};`);
+      if (String(curr.comment || '').trim()) statements.push(buildSqlServerColumnCommentSql(input.tableName, curr.name, curr.comment || ''));
+      return;
+    }
+
+    let currentName = orig.name;
+    if (curr.name !== orig.name) {
+      const plainTablePath = unquoteSqlIdentifierPath(input.tableName);
+      statements.push(`EXEC sp_rename '${escapeSqlString(`${plainTablePath}.${orig.name}`)}', '${escapeSqlString(curr.name)}', 'COLUMN';`);
+      currentName = curr.name;
+    }
+
+    if (curr.type !== orig.type || curr.nullable !== orig.nullable || Boolean(curr.isAutoIncrement) !== Boolean(orig.isAutoIncrement)) {
+      statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${buildStandardColumnDefinition({ ...curr, name: currentName, default: '' }, dbType, { includeNull: true, includeIdentity: false })};`);
+    }
+
+    const currDefault = normalizeDefaultText(curr.default);
+    const origDefault = normalizeDefaultText(orig.default);
+    if (currDefault !== origDefault) {
+      statements.push(buildSqlServerDefaultDropBatch(input.tableName, currentName));
+      if (currDefault) {
+        statements.push(`ALTER TABLE ${tableRef}\nADD DEFAULT ${formatDefaultExpression(currDefault, dbType)} FOR ${quoteIdentifierPart(currentName, dbType)};`);
+      }
+    }
+
+    if ((curr.comment || '') !== (orig.comment || '')) {
+      statements.push(buildSqlServerColumnCommentSql(input.tableName, currentName, curr.comment || ''));
+    }
+  });
+
+  const origPKKeys = input.originalColumns.filter((col) => col.key === 'PRI').map((col) => col._key);
+  const newPKKeys = input.columns.filter((col) => col.key === 'PRI').map((col) => col._key);
+  const keysChanged = origPKKeys.length !== newPKKeys.length || !origPKKeys.every((key) => newPKKeys.includes(key));
+  if (keysChanged) {
+    const { objectName } = splitQualifiedName(input.tableName);
+    const constraintName = quoteIdentifierPart(`PK_${objectName || 'table'}`, dbType);
+    if (origPKKeys.length > 0) {
+      statements.push(`-- SQL Server 删除旧主键需要原约束名；请先在索引页确认后删除。`);
+    }
+    if (newPKKeys.length > 0) {
+      const pkNames = input.columns.filter((col) => col.key === 'PRI').map((col) => quoteIdentifierPart(col.name, dbType)).join(', ');
+      statements.push(`ALTER TABLE ${tableRef}\nADD CONSTRAINT ${constraintName} PRIMARY KEY (${pkNames});`);
+    }
+  }
+
+  return statements.join('\n');
+};
+
+const buildSqliteAlterPreviewSql = (input: BuildAlterTablePreviewInput): string => {
+  const dbType = 'sqlite';
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
+  const statements: string[] = [];
+
+  input.originalColumns.forEach((orig) => {
+    if (!input.columns.find((col) => col._key === orig._key)) {
+      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, dbType)};`);
+    }
+  });
+
+  input.columns.forEach((curr) => {
+    const orig = input.originalColumns.find((col) => col._key === curr._key);
+    if (!orig) {
+      statements.push(`ALTER TABLE ${tableRef}\nADD COLUMN ${buildStandardColumnDefinition(curr, dbType)};`);
+      return;
+    }
+
+    let currentName = orig.name;
+    if (curr.name !== orig.name) {
+      statements.push(`ALTER TABLE ${tableRef}\nRENAME COLUMN ${quoteIdentifierPart(orig.name, dbType)} TO ${quoteIdentifierPart(curr.name, dbType)};`);
+      currentName = curr.name;
+    }
+    if (physicalDefinitionChanged(curr, orig) || (curr.comment || '') !== (orig.comment || '')) {
+      statements.push(`-- SQLite 不支持直接修改字段属性，请通过创建新表、迁移数据、替换旧表的方式处理字段 ${currentName}。`);
+    }
+  });
+
+  return statements.join('\n');
+};
+
+const buildDuckDbAlterPreviewSql = (input: BuildAlterTablePreviewInput): string => {
+  const dbType = 'duckdb';
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
+  const statements: string[] = [];
+
+  input.originalColumns.forEach((orig) => {
+    if (!input.columns.find((col) => col._key === orig._key)) {
+      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, dbType)};`);
+    }
+  });
+
+  input.columns.forEach((curr) => {
+    const orig = input.originalColumns.find((col) => col._key === curr._key);
+    if (!orig) {
+      statements.push(`ALTER TABLE ${tableRef}\nADD COLUMN ${buildStandardColumnDefinition(curr, dbType)};`);
+      return;
+    }
+
+    let currentName = orig.name;
+    if (curr.name !== orig.name) {
+      statements.push(`ALTER TABLE ${tableRef}\nRENAME COLUMN ${quoteIdentifierPart(orig.name, dbType)} TO ${quoteIdentifierPart(curr.name, dbType)};`);
+      currentName = curr.name;
+    }
+    if (curr.type !== orig.type) {
+      statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} SET DATA TYPE ${curr.type};`);
+    }
+    const currDefault = normalizeDefaultText(curr.default);
+    const origDefault = normalizeDefaultText(orig.default);
+    if (currDefault !== origDefault) {
+      if (currDefault) {
+        statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} SET DEFAULT ${formatDefaultExpression(currDefault, dbType)};`);
+      } else {
+        statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} DROP DEFAULT;`);
+      }
+    }
+    if (curr.nullable !== orig.nullable) {
+      statements.push(`ALTER TABLE ${tableRef}\nALTER COLUMN ${quoteIdentifierPart(currentName, dbType)} ${curr.nullable === 'NO' ? 'SET NOT NULL' : 'DROP NOT NULL'};`);
+    }
+    if ((curr.comment || '') !== (orig.comment || '')) {
+      statements.push(`-- DuckDB 不支持通过 COMMENT ON COLUMN 持久化字段备注，字段 ${currentName} 的备注仅保留在设计器预览中。`);
+    }
+  });
+
+  return statements.join('\n');
+};
+
+const buildLimitedBacktickAlterPreviewSql = (input: BuildAlterTablePreviewInput, dbType: string, label: string): string => {
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
+  const statements: string[] = [];
+
+  input.originalColumns.forEach((orig) => {
+    if (!input.columns.find((col) => col._key === orig._key)) {
+      statements.push(`ALTER TABLE ${tableRef}\nDROP COLUMN ${quoteIdentifierPart(orig.name, dbType)};`);
+    }
+  });
+
+  input.columns.forEach((curr) => {
+    const orig = input.originalColumns.find((col) => col._key === curr._key);
+    if (!orig) {
+      statements.push(`ALTER TABLE ${tableRef}\nADD COLUMN ${quoteIdentifierPart(curr.name, dbType)} ${curr.type};`);
+      if (curr.nullable === 'NO' || normalizeDefaultText(curr.default) || String(curr.comment || '').trim()) {
+        statements.push(`-- ${label} 的字段约束/默认值/备注语法与 MySQL 不同，已避免生成 MySQL 专属子句，请按目标库能力补充。`);
+      }
+      return;
+    }
+
+    let currentName = orig.name;
+    if (curr.name !== orig.name) {
+      statements.push(`ALTER TABLE ${tableRef}\nRENAME COLUMN ${quoteIdentifierPart(orig.name, dbType)} TO ${quoteIdentifierPart(curr.name, dbType)};`);
+      currentName = curr.name;
+    }
+    if (curr.type !== orig.type) {
+      statements.push(`ALTER TABLE ${tableRef}\nMODIFY COLUMN ${quoteIdentifierPart(currentName, dbType)} ${curr.type};`);
+    }
+    if (
+      curr.nullable !== orig.nullable ||
+      normalizeDefaultText(curr.default) !== normalizeDefaultText(orig.default) ||
+      (curr.comment || '') !== (orig.comment || '') ||
+      Boolean(curr.isAutoIncrement) !== Boolean(orig.isAutoIncrement)
+    ) {
+      statements.push(`-- ${label} 的字段约束/默认值/备注语法与 MySQL 不同，已避免生成 MySQL 专属子句，请按目标库能力补充。`);
+    }
+  });
+
+  return statements.join('\n');
+};
+
+export const buildAlterTablePreviewSql = (input: BuildAlterTablePreviewInput): string => {
+  const dbType = resolveSqlDialect(input.dbType);
+  if (isPgLikeDialect(dbType)) return buildPgLikeAlterPreviewSql({ ...input, dbType }, dbType);
+  if (isOracleLikeDialect(dbType)) return buildOracleLikeAlterPreviewSql({ ...input, dbType }, dbType);
+  if (isSqlServerDialect(dbType)) return buildSqlServerAlterPreviewSql({ ...input, dbType });
+  if (dbType === 'sqlite') return buildSqliteAlterPreviewSql({ ...input, dbType });
+  if (dbType === 'duckdb') return buildDuckDbAlterPreviewSql({ ...input, dbType });
+  if (dbType === 'clickhouse') return buildLimitedBacktickAlterPreviewSql({ ...input, dbType }, dbType, 'ClickHouse');
+  if (dbType === 'tdengine') return buildLimitedBacktickAlterPreviewSql({ ...input, dbType }, dbType, 'TDengine');
+  if (isMysqlFamilyDialect(dbType)) return buildMySqlAlterPreviewSql({ ...input, dbType }, dbType);
+  return buildPgLikeAlterPreviewSql({ ...input, dbType }, dbType);
 };

 export const hasAlterTableDraftChanges = (input: BuildAlterTablePreviewInput): boolean =>
  buildAlterTablePreviewSql(input).trim().length > 0;
+
+const buildCreateTableColumnDefinition = (column: EditableColumnSnapshot, dbType: string): string => {
+  if (isMysqlFamilyDialect(dbType)) {
+    return buildMySqlColumnDefinition(column, dbType);
+  }
+  if (isOracleLikeDialect(dbType)) {
+    return buildStandardColumnDefinition(column, dbType, { includeIdentity: true });
+  }
+  if (isSqlServerDialect(dbType)) {
+    return buildStandardColumnDefinition(column, dbType, { includeNull: true, includeIdentity: true });
+  }
+  if (dbType === 'clickhouse' || dbType === 'tdengine') {
+    return [quoteIdentifierPart(column.name, dbType), String(column.type || '').trim()].join(' ');
+  }
+  return buildStandardColumnDefinition(column, dbType);
+};
+
+const buildCreateColumnComments = (tableRef: string, input: BuildCreateTablePreviewInput, dbType: string): string[] => (
+  input.columns
+    .filter((column) => String(column.comment || '').trim())
+    .map((column) => {
+      if (isSqlServerDialect(dbType)) {
+        return buildSqlServerColumnCommentSql(input.tableName, column.name, column.comment || '');
+      }
+      if (isPgLikeDialect(dbType) || isOracleLikeDialect(dbType)) {
+        return buildColumnCommentSql(tableRef, column.name, column.comment || '', dbType);
+      }
+      return '';
+    })
+    .filter(Boolean)
+);
+
+export const buildCreateTablePreviewSql = (input: BuildCreateTablePreviewInput): string => {
+  const dbType = resolveSqlDialect(input.dbType);
+  const tableRef = quoteIdentifierPath(input.tableName, dbType);
+  const colDefs = input.columns.map((column) => buildCreateTableColumnDefinition(column, dbType));
+  const pkColumns = input.columns.filter((column) => column.key === 'PRI');
+  if (pkColumns.length > 0) {
+    const pkNames = pkColumns.map((column) => quoteIdentifierPart(column.name, dbType)).join(', ');
+    colDefs.push(`PRIMARY KEY (${pkNames})`);
+  }
+
+  const createSql = `CREATE TABLE ${tableRef} (\n  ${colDefs.join(',\n  ')}\n)`;
+  const comments = buildCreateColumnComments(tableRef, input, dbType);
+
+  if (dbType === 'mysql' || dbType === 'mariadb') {
+    const charset = String(input.charset || '').trim();
+    const collation = String(input.collation || '').trim();
+    const charsetSql = charset ? ` DEFAULT CHARSET=${charset}` : '';
+    const collationSql = collation ? ` COLLATE=${collation}` : '';
+    return `${createSql} ENGINE=InnoDB${charsetSql}${collationSql};`;
+  }
+
+  if (dbType === 'clickhouse') {
+    return `${createSql}\nENGINE = MergeTree\nORDER BY tuple();`;
+  }
+
+  const suffixComments = comments.length > 0 ? `\n${comments.join('\n')}` : '';
+  if (dbType === 'tdengine' && !input.columns.some((column) => /^timestamp$/i.test(String(column.type || '').trim()))) {
+    return `${createSql};\n-- TDengine 普通表通常需要 TIMESTAMP 时间列，执行前请确认表模型。${suffixComments}`;
+  }
+
+  if (isBacktickIdentifierDialect(dbType) && dbType !== 'mysql' && dbType !== 'mariadb') {
+    return `${createSql};${suffixComments}`;
+  }
+
+  return `${createSql};${suffixComments}`;
+};