fix: When agents use data tables, different users influence each other (#565)

backend/infra/impl/sqlparser/sql_parser.go

@@ -24,6 +24,7 @@ import (
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/format"
 	"github.com/pingcap/tidb/pkg/parser/mysql"
+	"github.com/pingcap/tidb/pkg/parser/opcode"
 	_ "github.com/pingcap/tidb/pkg/parser/test_driver"
 
 	"github.com/coze-dev/coze-studio/backend/infra/contract/sqlparser"
@@ -411,3 +412,81 @@ func (p *Impl) GetInsertDataNums(sql string) (int, error) {
 
 	return len(insert.Lists), nil
 }
+func (p *Impl) AppendSQLFilter(sql string, op sqlparser.SQLFilterOp, filter string) (string, error) {
+	if sql == "" {
+		return "", fmt.Errorf("empty SQL statement")
+	}
+	if op == "" || (op != sqlparser.SQLFilterOpAnd && op != sqlparser.SQLFilterOpOr) {
+		return "", fmt.Errorf("invalid filter operator: %s", op)
+	}
+	if filter == "" {
+		return "", fmt.Errorf("empty filter condition")
+	}
+	stmtNode, err := p.parser.ParseOneStmt(sql, mysql.UTF8MB4Charset, mysql.UTF8MB4GeneralCICollation)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse SQL: %v", err)
+	}
+	// extract WHERE clause
+	var originalWhere ast.ExprNode
+	switch stmt := stmtNode.(type) {
+	case *ast.SelectStmt:
+		originalWhere = stmt.Where
+	case *ast.UpdateStmt:
+		originalWhere = stmt.Where
+	case *ast.DeleteStmt:
+		originalWhere = stmt.Where
+	default:
+		return "", fmt.Errorf("append filter condition failed: only support SELECT/UPDATE/DELETE")
+	}
+	tmpSQL := fmt.Sprintf("SELECT * FROM tmp WHERE %s", filter)
+	tmpNode, err := p.parser.ParseOneStmt(tmpSQL, mysql.UTF8MB4Charset, mysql.UTF8MB4GeneralCICollation)
+	if err != nil {
+		return "", fmt.Errorf("parse filter condition failed: %v", err)
+	}
+	newExpr := tmpNode.(*ast.SelectStmt).Where
+	mergedExpr := mergeExpr(originalWhere, newExpr, op)
+	// update AST
+	switch stmt := stmtNode.(type) {
+	case *ast.SelectStmt:
+		stmt.Where = mergedExpr
+	case *ast.UpdateStmt:
+		stmt.Where = mergedExpr
+	case *ast.DeleteStmt:
+		stmt.Where = mergedExpr
+	}
+
+	// regenerate SQL
+	var sb strings.Builder
+	flags := format.RestoreStringSingleQuotes | format.RestoreStringWithoutCharset | format.RestoreNameBackQuotes
+	restoreCtx := format.NewRestoreCtx(flags, &sb)
+	if err := stmtNode.Restore(restoreCtx); err != nil {
+		return "", fmt.Errorf("gen SQL failed: %v", err)
+	}
+	return sb.String(), nil
+}
+
+func mergeExpr(left, right ast.ExprNode, op sqlparser.SQLFilterOp) ast.ExprNode {
+	if left == nil {
+		return right
+	}
+	if right == nil {
+		return left
+	}
+
+	switch op {
+	case sqlparser.SQLFilterOpAnd:
+		return &ast.BinaryOperationExpr{
+			Op: opcode.LogicAnd,
+			L:  left,
+			R:  right,
+		}
+	case sqlparser.SQLFilterOpOr:
+		return &ast.BinaryOperationExpr{
+			Op: opcode.LogicOr,
+			L:  left,
+			R:  right,
+		}
+	default:
+		return nil
+	}
+}