✨ feat(db-ui): 修复金仓打开表报错并增强结果页编辑体验

- postgres/kingbase 查询前自动清洗 ""ident"" 形式的非法标识符
  - 结果表支持单元格弹窗编辑，提升 JSON/长文本可编辑性
  - 修复查询结果表头与数据列宽度不对齐问题

internal/app/sql_sanitize.go

@@ -0,0 +1,219 @@
+package app
+
+import (
+	"strings"
+	"unicode"
+)
+
+func sanitizeSQLForPgLike(dbType string, query string) string {
+	switch strings.ToLower(strings.TrimSpace(dbType)) {
+	case "postgres", "kingbase":
+		return fixBrokenDoubleDoubleQuotedIdent(query)
+	default:
+		return query
+	}
+}
+
+// fixBrokenDoubleDoubleQuotedIdent fixes accidental identifiers like:
+//   SELECT * FROM ""schema"".""table""
+// which can be produced when a quoted identifier gets wrapped by quotes again.
+//
+// It is intentionally conservative:
+// - only runs outside strings/comments/dollar-quoted blocks
+// - does not touch valid escaped-quote sequences inside quoted identifiers (e.g. "a""b")
+func fixBrokenDoubleDoubleQuotedIdent(query string) string {
+	if !strings.Contains(query, `""`) {
+		return query
+	}
+
+	var b strings.Builder
+	b.Grow(len(query))
+
+	inSingle := false
+	inDoubleIdent := false
+	inLineComment := false
+	inBlockComment := false
+	dollarTag := ""
+
+	for i := 0; i < len(query); i++ {
+		ch := query[i]
+		next := byte(0)
+		if i+1 < len(query) {
+			next = query[i+1]
+		}
+
+		if inLineComment {
+			b.WriteByte(ch)
+			if ch == '\n' {
+				inLineComment = false
+			}
+			continue
+		}
+		if inBlockComment {
+			b.WriteByte(ch)
+			if ch == '*' && next == '/' {
+				b.WriteByte('/')
+				i++
+				inBlockComment = false
+			}
+			continue
+		}
+		if dollarTag != "" {
+			if strings.HasPrefix(query[i:], dollarTag) {
+				b.WriteString(dollarTag)
+				i += len(dollarTag) - 1
+				dollarTag = ""
+				continue
+			}
+			b.WriteByte(ch)
+			continue
+		}
+		if inSingle {
+			b.WriteByte(ch)
+			if ch == '\'' {
+				// escaped single quote
+				if next == '\'' {
+					b.WriteByte('\'')
+					i++
+					continue
+				}
+				inSingle = false
+			}
+			continue
+		}
+		if inDoubleIdent {
+			b.WriteByte(ch)
+			if ch == '"' {
+				// escaped quote inside identifier
+				if next == '"' {
+					b.WriteByte('"')
+					i++
+					continue
+				}
+				inDoubleIdent = false
+			}
+			continue
+		}
+
+		// --- Outside of all string/comment blocks ---
+		if ch == '-' && next == '-' {
+			b.WriteByte(ch)
+			b.WriteByte('-')
+			i++
+			inLineComment = true
+			continue
+		}
+		if ch == '/' && next == '*' {
+			b.WriteByte(ch)
+			b.WriteByte('*')
+			i++
+			inBlockComment = true
+			continue
+		}
+		if ch == '\'' {
+			b.WriteByte(ch)
+			inSingle = true
+			continue
+		}
+		if ch == '$' {
+			if tag := parseDollarTag(query[i:]); tag != "" {
+				b.WriteString(tag)
+				i += len(tag) - 1
+				dollarTag = tag
+				continue
+			}
+		}
+
+		// Fix: ""ident"" -> "ident" (only when it looks like a plain identifier)
+		if ch == '"' && next == '"' {
+			prevIsQuote := i > 0 && query[i-1] == '"'
+			nextIsQuote := i+2 < len(query) && query[i+2] == '"'
+			if !prevIsQuote && !nextIsQuote {
+				if replacement, advance, ok := tryFixDoubleDoubleQuotedIdent(query, i); ok {
+					b.WriteString(replacement)
+					i = advance - 1
+					continue
+				}
+			}
+		}
+
+		if ch == '"' {
+			b.WriteByte(ch)
+			inDoubleIdent = true
+			continue
+		}
+
+		b.WriteByte(ch)
+	}
+
+	return b.String()
+}
+
+func tryFixDoubleDoubleQuotedIdent(query string, start int) (replacement string, advance int, ok bool) {
+	// start points at the first quote of `""...""`
+	if start < 0 || start+1 >= len(query) {
+		return "", 0, false
+	}
+	if query[start] != '"' || query[start+1] != '"' {
+		return "", 0, false
+	}
+	if start > 0 && query[start-1] == '"' {
+		return "", 0, false
+	}
+	if start+2 < len(query) && query[start+2] == '"' {
+		return "", 0, false
+	}
+
+	contentStart := start + 2
+	j := contentStart
+	for j+1 < len(query) {
+		if query[j] == '"' && query[j+1] == '"' {
+			// ensure closing pair is not part of a triple quote
+			if j+2 < len(query) && query[j+2] == '"' {
+				j++
+				continue
+			}
+			content := strings.TrimSpace(query[contentStart:j])
+			if looksLikeIdentifierContent(content) {
+				return `"` + content + `"`, j + 2, true
+			}
+			return "", 0, false
+		}
+		// Fast abort: identifier-like content should not span lines.
+		if query[j] == '\n' || query[j] == '\r' {
+			break
+		}
+		j++
+	}
+	return "", 0, false
+}
+
+func looksLikeIdentifierContent(s string) bool {
+	if strings.TrimSpace(s) == "" {
+		return false
+	}
+	for _, r := range s {
+		if r == '_' || r == '$' || r == '-' || unicode.IsLetter(r) || unicode.IsDigit(r) {
+			continue
+		}
+		return false
+	}
+	return true
+}
+
+func parseDollarTag(s string) string {
+	// Match: $tag$ where tag is [A-Za-z0-9_]* (can be empty => $$)
+	if len(s) < 2 || s[0] != '$' {
+		return ""
+	}
+	for i := 1; i < len(s); i++ {
+		c := s[i]
+		if c == '$' {
+			return s[:i+1]
+		}
+		if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_') {
+			return ""
+		}
+	}
+	return ""
+}