FlowiseAI/Flowise · error · Error

Invalid SQL statement: multiple statements are not allowed

Error message

Invalid SQL statement: multiple statements are not allowed

What it means

Thrown by assertReadOnlySqlStatement (packages/components/src/validator.ts:389) when, after stripping one optional trailing semicolon, the statement still contains ';'. This blocks stacked queries (e.g. 'SELECT 1; DROP TABLE x') which SQLite/TypeORM would otherwise execute in sequence.

Source

Thrown at packages/components/src/validator.ts:389

 * All legitimate queries issued against sqlite by this chain (including langchain's own
 * schema introspection, which uses `pragma_table_info()` as a table-valued function
 * inside a SELECT) are single SELECT/WITH statements, so this restriction does not
 * affect normal operation.
 *
 * @param {string} sql The SQL statement to validate
 * @throws {Error} If the statement is not a single read-only SELECT/WITH statement
 */
export const assertReadOnlySqlStatement = (sql: string): void => {
    if (!sql || typeof sql !== 'string') {
        throw new Error('Invalid SQL statement: statement is required and must be a string')
    }

    let trimmed = sql.trim()
    // Strip at most one trailing semicolon (+ trailing whitespace)
    trimmed = trimmed.replace(/;\s*$/, '')

    if (trimmed.includes(';')) {
        throw new Error('Invalid SQL statement: multiple statements are not allowed')
    }

    if (!/^(SELECT|WITH)\b/i.test(trimmed)) {
        throw new Error('Invalid SQL statement: only read-only SELECT/WITH statements are allowed')
    }

    if (/load_extension\s*\(/i.test(trimmed)) {
        throw new Error('Invalid SQL statement: load_extension is not allowed')
    }
}

/**
 * Sanitize a file name to prevent path traversal attacks.
 * Strips common storage prefixes, extracts the basename, runs it through
 * the `sanitize-filename` package, and rejects anything that still looks unsafe.
 *
 * @param {string} name The file name to sanitize
 */

View on GitHub (pinned to abe4a8601a)

Solutions

1. Send only one SELECT/WITH statement per call.
2. Strip trailing comments and the final ';' before submitting.
3. Tune the chain's prompt to forbid multi-statement output.
4. If you need multiple queries, run them as separate validated calls.

Example fix

// before
sql = 'SELECT * FROM users; SELECT * FROM orders;'

// after
sql = 'SELECT * FROM users'   // one statement, no trailing ';'

const one = String(sql ?? '').trim().replace(/;\s*$/, '');
if (one.includes(';')) throw new Error('multi-statement SQL rejected');
assertReadOnlySqlStatement(one);

const isSingleStatement = (s: unknown): s is string => typeof s === 'string' && !s.trim().replace(/;\s*$/, '').includes(';');

try { assertReadOnlySqlStatement(sql) } catch (e) { if (e instanceof Error && /multiple statements/.test(e.message)) { sql = sql.split(';')[0] } else throw e }

When it happens

Trigger: LLM-generated SQL contains multiple statements, e.g. 'SELECT * FROM t; SELECT * FROM u' or a trailing comment+semicolon like 'SELECT 1; -- done'. Any ';' beyond the single permitted trailing one trips it.

Common situations: LLMs trained on multi-statement scripts; copy-pasted schema-setup SQL; CTEs that incorrectly embed ';'.

Related errors

• Invalid SQL statement: only read-only SELECT/WITH statements
• Invalid SQL statement: statement is required and must be a s
• Invalid SQL statement: load_extension is not allowed
• Invalid SQLite path: path traversal attempt detected
• Invalid SQLite path: encoded path traversal attempt detected

AI-assisted analysis of FlowiseAI/Flowise@abe4a8601a (2026-08-12). Data as JSON: /api/errors/8f986b7b535ef106. Report an issue: GitHub.