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 - Malformed SQL statements
• UNKNOWN_IDENTIFIER - Undefined table or column names
• UNKNOWN_FUNCTION - Non-existent functions
• UNKNOWN_TYPE - Unsupported data types

Type and Conversion Errors¶

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

• ILLEGAL_TYPE_OF_ARGUMENT - Wrong argument types for functions
• TYPE_MISMATCH - Incompatible data types in operations
• NO_COMMON_TYPE - Cannot determine common type for operation
• CANNOT_PARSE_DATE - Invalid date string formats
• CANNOT_PARSE_DATETIME - Invalid datetime string formats
• CANNOT_PARSE_TEXT - Text parsing failures
• CANNOT_READ_ARRAY_FROM_TEXT - Array parsing issues

Function and Argument Errors¶

These errors occur when functions are used incorrectly:

• BAD_ARGUMENTS - Invalid function arguments
• NUMBER_OF_ARGUMENTS_DOESNT_MATCH - Wrong number of function arguments
• TOO_FEW_ARGUMENTS_FOR_FUNCTION - Missing required arguments

Aggregation and Grouping Errors¶

These errors happen with aggregate functions and GROUP BY clauses:

• NOT_AN_AGGREGATE - Non-aggregate functions in aggregate context
• ILLEGAL_AGGREGATION - Invalid aggregation operations
• ILLEGAL_COLUMN - Unsupported column usage

JOIN and Relationship Errors¶

These errors occur with table joins and relationships:

• INVALID_JOIN_ON_EXPRESSION - Invalid JOIN conditions
• UNSUPPORTED_JOIN_KEYS - Unsupported JOIN key types
• 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 - Query result too large
• QUERY_WITH_SAME_ID_IS_ALREADY_RUNNING - Duplicate query execution

Table and Engine Errors¶

These errors occur with table operations and engines:

• ILLEGAL_FINAL - FINAL keyword usage issues
• MULTIPLE_EXPRESSIONS_FOR_ALIAS - Alias conflicts

System and Implementation Errors¶

These errors relate to system limitations and unsupported features:

• NOT_IMPLEMENTED - Unsupported features or operations
• UNSUPPORTED_METHOD - Unsupported methods or operations

Quick reference¶

Most common errors¶

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¶

• Troubleshooting Overview - General troubleshooting guide
• Common Error Patterns - Recurring error patterns
• ClickHouse Functions - Function documentation
• Data Types - ClickHouse data type reference