Fix qualified table name parsing in trigger bodies

parser.go

@@ -1,6 +1,7 @@
 package sql
 
 import (
+	"fmt"
 	"io"
 	"strings"
 )
@@ -1304,9 +1305,9 @@ func (p *Parser) parseTriggerBodyStatement() (stmt Statement, err error) {
 	case INSERT, REPLACE:
 		stmt, err = p.parseInsertStatement(nil)
 	case UPDATE:
-		stmt, err = p.parseUpdateStatement(nil)
+		stmt, err = p.parseTriggerBodyUpdateStatement(nil)
 	case DELETE:
-		stmt, err = p.parseDeleteStatement(nil)
+		stmt, err = p.parseTriggerBodyDeleteStatement(nil)
 	case WITH:
 		stmt, err = p.parseWithStatement()
 	default:
@@ -1325,6 +1326,175 @@ func (p *Parser) parseTriggerBodyStatement() (stmt Statement, err error) {
 	return stmt, nil
 }
 
+// parseTriggerBodyDeleteStatement parses a DELETE statement within a trigger body.
+// It differs from parseDeleteStatement by only allowing unqualified table names.
+func (p *Parser) parseTriggerBodyDeleteStatement(withClause *WithClause) (_ *DeleteStatement, err error) {
+	assert(p.peek() == DELETE)
+
+	var stmt DeleteStatement
+	stmt.WithClause = withClause
+
+	// Parse "DELETE FROM tbl"
+	stmt.Delete, _, _ = p.scan()
+	if p.peek() != FROM {
+		return &stmt, p.errorExpected(p.pos, p.tok, "FROM")
+	}
+	stmt.From, _, _ = p.scan()
+	if !isIdentToken(p.peek()) {
+		return nil, p.errorExpected(p.pos, p.tok, "table name")
+	}
+	ident, _ := p.parseIdent("table name")
+
+	// In trigger bodies, only unqualified table names are allowed
+	if err = p.validateUnqualifiedTableName(ident); err != nil {
+		return &stmt, err
+	}
+	stmt.Table = &QualifiedTableName{Name: ident}
+
+	// Parse WHERE clause.
+	if p.peek() == WHERE {
+		stmt.Where, _, _ = p.scan()
+		if stmt.WhereExpr, err = p.ParseExpr(); err != nil {
+			return &stmt, err
+		}
+	}
+
+	// Parse ORDER BY clause. This differs from the SELECT parsing in that
+	// if an ORDER BY is specified then the LIMIT is required.
+	if p.peek() == ORDER || p.peek() == LIMIT {
+		if p.peek() == ORDER {
+			stmt.Order, _, _ = p.scan()
+			if p.peek() != BY {
+				return &stmt, p.errorExpected(p.pos, p.tok, "BY")
+			}
+			stmt.OrderBy, _, _ = p.scan()
+
+			for {
+				term, err := p.parseOrderingTerm()
+				if err != nil {
+					return &stmt, err
+				}
+				stmt.OrderingTerms = append(stmt.OrderingTerms, term)
+
+				if p.peek() != COMMA {
+					break
+				}
+				p.scan()
+			}
+		}
+
+		// Parse LIMIT/OFFSET clause.
+		if p.peek() != LIMIT {
+			return &stmt, p.errorExpected(p.pos, p.tok, "LIMIT")
+		}
+		stmt.Limit, _, _ = p.scan()
+		if stmt.LimitExpr, err = p.ParseExpr(); err != nil {
+			return &stmt, err
+		}
+
+		if p.peek() == OFFSET {
+			stmt.Offset, _, _ = p.scan()
+			if stmt.OffsetExpr, err = p.ParseExpr(); err != nil {
+				return &stmt, err
+			}
+		}
+	}
+
+	return &stmt, nil
+}
+
+// parseTriggerBodyUpdateStatement parses an UPDATE statement within a trigger body.
+// It differs from parseUpdateStatement by only allowing unqualified table names.
+func (p *Parser) parseTriggerBodyUpdateStatement(withClause *WithClause) (_ *UpdateStatement, err error) {
+	assert(p.peek() == UPDATE)
+
+	var stmt UpdateStatement
+	stmt.WithClause = withClause
+
+	stmt.Update, _, _ = p.scan()
+	if p.peek() == OR {
+		stmt.UpdateOr, _, _ = p.scan()
+
+		switch p.peek() {
+		case ROLLBACK:
+			stmt.UpdateOrRollback, _, _ = p.scan()
+		case REPLACE:
+			stmt.UpdateOrReplace, _, _ = p.scan()
+		case ABORT:
+			stmt.UpdateOrAbort, _, _ = p.scan()
+		case FAIL:
+			stmt.UpdateOrFail, _, _ = p.scan()
+		case IGNORE:
+			stmt.UpdateOrIgnore, _, _ = p.scan()
+		default:
+			return &stmt, p.errorExpected(p.pos, p.tok, "ROLLBACK, REPLACE, ABORT, FAIL, or IGNORE")
+		}
+	}
+
+	if !isIdentToken(p.peek()) {
+		return nil, p.errorExpected(p.pos, p.tok, "table name")
+	}
+	ident, _ := p.parseIdent("table name")
+
+	// In trigger bodies, only unqualified table names are allowed
+	if err = p.validateUnqualifiedTableName(ident); err != nil {
+		return &stmt, err
+	}
+	stmt.Table = &QualifiedTableName{Name: ident}
+
+	// Parse SET + list of assignments.
+	if p.peek() != SET {
+		return &stmt, p.errorExpected(p.pos, p.tok, "SET")
+	}
+	stmt.Set, _, _ = p.scan()
+
+	for {
+		assignment, err := p.parseAssignment()
+		if err != nil {
+			return &stmt, err
+		}
+		stmt.Assignments = append(stmt.Assignments, assignment)
+
+		if p.peek() != COMMA {
+			break
+		}
+		p.scan()
+	}
+
+	// Parse WHERE clause.
+	if p.peek() == WHERE {
+		stmt.Where, _, _ = p.scan()
+		if stmt.WhereExpr, err = p.ParseExpr(); err != nil {
+			return &stmt, err
+		}
+	}
+
+	// Parse optional RETURNING clause.
+	if p.peek() == RETURNING {
+		if stmt.ReturningClause, err = p.parseReturningClause(); err != nil {
+			return &stmt, err
+		}
+	}
+
+	return &stmt, nil
+}
+
+// validateUnqualifiedTableName ensures that the next tokens do not form
+// a qualified table name (schema.table or table alias).
+func (p *Parser) validateUnqualifiedTableName(ident *Ident) error {
+	// Check for schema qualification (schema.table)
+	if p.peek() == DOT {
+		return fmt.Errorf("qualified table names not allowed in trigger body")
+	}
+
+	// Check for table alias
+	if tok := p.peek(); tok == AS || isIdentToken(tok) {
+		return fmt.Errorf("qualified table names not allowed in trigger body")
+	}
+
+	return nil
+}
+
 func (p *Parser) parseDropTriggerStatement(dropPos Pos) (_ *DropTriggerStatement, err error) {
 	assert(p.peek() == TRIGGER)
 

parser_test.go

@@ -1860,6 +1860,12 @@ func TestParser_ParseStatement(t *testing.T) {
 			End: pos(83),
 		})
 
+		// Test cases that should fail due to qualified table names in trigger body
+		AssertParseStatementError(t, `CREATE TRIGGER trig AFTER DELETE ON tbl BEGIN DELETE FROM host h; END`, `qualified table names not allowed in trigger body`)
+		AssertParseStatementError(t, `CREATE TRIGGER trig AFTER DELETE ON tbl BEGIN UPDATE host h SET x = 1; END`, `qualified table names not allowed in trigger body`)
+		AssertParseStatementError(t, `CREATE TRIGGER trig AFTER DELETE ON tbl BEGIN DELETE FROM schema.host; END`, `qualified table names not allowed in trigger body`)
+		AssertParseStatementError(t, `CREATE TRIGGER trig AFTER DELETE ON tbl BEGIN UPDATE schema.host SET x = 1; END`, `qualified table names not allowed in trigger body`)
+
 		AssertParseStatementError(t, `CREATE TRIGGER`, `1:14: expected index name, found 'EOF'`)
 		AssertParseStatementError(t, `CREATE TRIGGER IF`, `1:17: expected NOT, found 'EOF'`)
 		AssertParseStatementError(t, `CREATE TRIGGER IF NOT`, `1:21: expected EXISTS, found 'EOF'`)