---
title: ClickHouse Errors
meta:
  description: Comprehensive guide to ClickHouse database errors in Tinybird. Find detailed explanations and solutions for common error codes.
---

# ClickHouse Errors

This section provides detailed documentation for the most common ClickHouse database errors you'll encounter when working with Tinybird. Each error page includes explanations, examples, and step-by-step solutions.

## Error categories

### Syntax and Structure Errors

These errors occur when SQL syntax is incorrect or queries are malformed:

- [`SYNTAX_ERROR`](/sql-reference/clickhouse-errors/SYNTAX_ERROR) - Malformed SQL statements
- [`UNKNOWN_IDENTIFIER`](/sql-reference/clickhouse-errors/UNKNOWN_IDENTIFIER) - Undefined table or column names
- [`UNKNOWN_FUNCTION`](/sql-reference/clickhouse-errors/UNKNOWN_FUNCTION) - Non-existent functions
- [`UNKNOWN_TYPE`](/sql-reference/clickhouse-errors/UNKNOWN_TYPE) - Unsupported data types

### Type and Conversion Errors

These errors happen when data types are incompatible or conversion fails:

- [`ILLEGAL_TYPE_OF_ARGUMENT`](/sql-reference/clickhouse-errors/ILLEGAL_TYPE_OF_ARGUMENT) - Wrong argument types for functions
- [`TYPE_MISMATCH`](/sql-reference/clickhouse-errors/TYPE_MISMATCH) - Incompatible data types in operations
- [`NO_COMMON_TYPE`](/sql-reference/clickhouse-errors/NO_COMMON_TYPE) - Cannot determine common type for operation
- [`CANNOT_PARSE_DATE`](/sql-reference/clickhouse-errors/CANNOT_PARSE_DATE) - Invalid date string formats
- [`CANNOT_PARSE_DATETIME`](/sql-reference/clickhouse-errors/CANNOT_PARSE_DATETIME) - Invalid datetime string formats
- [`CANNOT_PARSE_TEXT`](/sql-reference/clickhouse-errors/CANNOT_PARSE_TEXT) - Text parsing failures
- [`CANNOT_READ_ARRAY_FROM_TEXT`](/sql-reference/clickhouse-errors/CANNOT_READ_ARRAY_FROM_TEXT) - Array parsing issues

### Function and Argument Errors

These errors occur when functions are used incorrectly:

- [`BAD_ARGUMENTS`](/sql-reference/clickhouse-errors/BAD_ARGUMENTS) - Invalid function arguments
- [`NUMBER_OF_ARGUMENTS_DOESNT_MATCH`](/sql-reference/clickhouse-errors/NUMBER_OF_ARGUMENTS_DOESNT_MATCH) - Wrong number of function arguments

### Aggregation and Grouping Errors

These errors happen with aggregate functions and GROUP BY clauses:

- [`NOT_AN_AGGREGATE`](/sql-reference/clickhouse-errors/NOT_AN_AGGREGATE) - Non-aggregate functions in aggregate context
- [`ILLEGAL_AGGREGATION`](/sql-reference/clickhouse-errors/ILLEGAL_AGGREGATION) - Invalid aggregation operations
- [`ILLEGAL_COLUMN`](/sql-reference/clickhouse-errors/ILLEGAL_COLUMN) - Unsupported column usage

### JOIN and Relationship Errors

These errors occur with table joins and relationships:

- [`INVALID_JOIN_ON_EXPRESSION`](/sql-reference/clickhouse-errors/INVALID_JOIN_ON_EXPRESSION) - Invalid JOIN conditions
- [`UNSUPPORTED_JOIN_KEYS`](/sql-reference/clickhouse-errors/UNSUPPORTED_JOIN_KEYS) - Unsupported JOIN key types
- [`UNION_ALL_RESULT_STRUCTURES_MISMATCH`](/sql-reference/clickhouse-errors/UNION_ALL_RESULT_STRUCTURES_MISMATCH) - Incompatible UNION structures

### Query and Performance Errors

These errors relate to query execution and performance:

- [`TOO_MANY_ROWS_OR_BYTES`](/sql-reference/clickhouse-errors/TOO_MANY_ROWS_OR_BYTES) - Query result too large
- [`QUERY_WITH_SAME_ID_IS_ALREADY_RUNNING`](/sql-reference/clickhouse-errors/QUERY_WITH_SAME_ID_IS_ALREADY_RUNNING) - Duplicate query execution

### Table and Engine Errors

These errors occur with table operations and engines:

- [`ILLEGAL_FINAL`](/sql-reference/clickhouse-errors/ILLEGAL_FINAL) - FINAL keyword usage issues
- [`MULTIPLE_EXPRESSIONS_FOR_ALIAS`](/sql-reference/clickhouse-errors/MULTIPLE_EXPRESSIONS_FOR_ALIAS) - Alias conflicts

### System and Implementation Errors

These errors relate to system limitations and unsupported features:

- [`NOT_IMPLEMENTED`](/sql-reference/clickhouse-errors/NOT_IMPLEMENTED) - Unsupported features or operations
- [`UNSUPPORTED_METHOD`](/sql-reference/clickhouse-errors/UNSUPPORTED_METHOD) - Unsupported methods or operations

## Quick reference

### Most common errors

| Error | Frequency | Typical Cause |
|-------|-----------|---------------|
| `UNKNOWN_IDENTIFIER` | Very High | Misspelled column/table names |
| `NOT_AN_AGGREGATE` | High | Non-aggregate columns in GROUP BY |
| `ILLEGAL_TYPE_OF_ARGUMENT` | High | Wrong argument types |
| `TOO_MANY_ROWS_OR_BYTES` | Medium | Large result sets |

### Error prevention tips

- **Always test queries** with small datasets first
- **Use appropriate data types** for your columns
- **Check function documentation** before using new functions
- **Use aliases** to avoid column name conflicts
- **Implement proper error handling** in your applications

## Need help with a specific error?

If you can't find your error in this documentation:

1. **Search for the error code** in the ClickHouse documentation
2. **Check the error context** - what operation were you performing?
3. **Simplify your query** - try to isolate the problematic part
4. **Use the Query Builder** - test your query step by step

## See also

- [SQL Reference Overview](/sql-reference) - SQL reference guide
- [Common Error Patterns](/forward/dev-reference/common-error-patterns) - Recurring error patterns
- [ClickHouse Functions](/sql-reference/functions) - Function documentation
- [Data Types](/sql-reference/data-types) - ClickHouse data type reference