What causes ""ChildTable multi insert not provided"" in MyCATApache/Mycat-Server?

Split the multi-row insert into separate single-row INSERT statements, one per child row

MyCATApache/Mycat-Server · error · SQLNonTransientException

"ChildTable multi insert not provided"

Error message

"ChildTable multi insert not provided"

What it means

Mycat's child-table (ER partition) insert routing only supports single-row inserts. When parserChildTable detects a multi-row VALUES clause (isMultiInsert), it cannot distribute individual rows per parent lookup and throws SQLNonTransientException.

Solutions

Split the multi-row insert into separate single-row INSERT statements, one per child row
If the table does not truly need ER partitioning, remove isChildTable/joinKey config and use normal sharding (then batch inserts go through parserBatchInsert)
Perform the batch insert directly on backend nodes when the parent node is known
Wrap rows in a transaction of individual inserts to keep atomicity

Example fix

// before
INSERT INTO order_detail (id, order_id, item) VALUES (1,100,'a'),(2,100,'b');
// after
INSERT INTO order_detail (id, order_id, item) VALUES (1,100,'a');
INSERT INTO order_detail (id, order_id, item) VALUES (2,100,'b');

Defensive patterns

Strategy: validation

Validate before calling

// refuse multi-row inserts into child tables before routing
if (extractInsertColumns(sql) != null && countValuesTuples(sql) > 1 && tableConfig.isChildTable()) {
    throw new IllegalArgumentException("Child table inserts must be single-row; split the batch");
}

Type guard

static boolean isSingleRowInsert(MySqlInsertStatement ins) {
    return ins.getValuesList() == null || ins.getValuesList().size() <= 1;
}

Try / catch

try {
    insertBatch(rows);
} catch (SQLNonTransientException e) {
    if ("ChildTable multi insert not provided".equals(e.getMessage())) {
        // fall back to per-row inserts inside a transaction
        rows.forEach(this::insertSingle);
        return;
    }
    throw e;
}

Prevention

Split child-table batches into single-row inserts within a transaction
Configure ORMs (MyBatis foreach, Hibernate JDBC batch) not to rewrite into multi-values for child tables
Check isChildTable config before choosing a batch-insert strategy

When it happens

Trigger: `INSERT INTO child_table (..., joinKey, ...) VALUES (...), (...), ...` — a batch/multi-row insert — into a table marked as childTable in schema.xml.

Common situations: ORM batch flush (Hibernate/JDBC batch rewriting as multi-values); bulk data seeding scripts copying many child rows at once; MyBatis foreach-generated multi-row inserts.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/a817f49ff411e56c. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/route/parser/druid/impl/DruidInsertParser.java:133

	private boolean isMultiInsert(MySqlInsertStatement insertStmt) {
		return (insertStmt.getValuesList() != null && insertStmt.getValuesList().size() > 1) || insertStmt.getQuery() != null;
	}
	
	private RouteResultset parserChildTable(SchemaConfig schema, RouteResultset rrs,
			String tableName, MySqlInsertStatement insertStmt) throws SQLNonTransientException {
		TableConfig tc = schema.getTables().get(tableName);
		
		String joinKey = tc.getJoinKey();
		int joinKeyIndex = getJoinKeyIndex(insertStmt.getColumns(), joinKey);
		if(joinKeyIndex == -1) {
			String inf = "joinKey not provided :" + tc.getJoinKey()+ "," + insertStmt;
			LOGGER.warn(inf);
			throw new SQLNonTransientException(inf);
		}
		if(isMultiInsert(insertStmt)) {
			String msg = "ChildTable multi insert not provided" ;
			LOGGER.warn(msg);
			throw new SQLNonTransientException(msg);
		}
		
		String joinKeyVal = insertStmt.getValues().getValues().get(joinKeyIndex).toString();

		
		String sql = insertStmt.toString();
		
		// try to route by ER parent partion key
		RouteResultset theRrs = RouterUtil.routeByERParentKey(null,schema, ServerParse.INSERT,sql, rrs, tc,joinKeyVal);
		if (theRrs != null) {
			rrs.setFinishedRoute(true);
			return theRrs;
		}

		// route by sql query root parent's datanode
		String findRootTBSql = tc.getLocateRTableKeySql().toLowerCase() + joinKeyVal;
		if (LOGGER.isDebugEnabled()) {
			LOGGER.debug("find root parent's node sql "+ findRootTBSql);

View on GitHub (pinned to 65f8d8beb7)