Error Code 1005: Why Can't I Create This Table and How Do I Fix It?

Error Code: 1005: Understanding the Root Cause and Solving the Problem

The error code 1005, "Can't create table '...' (errno: 150)", encountered during database operations indicates an inability to create a table due to an underlying reason. This error often arises when attempting to add a foreign key constraint to an existing table.

The root cause of this error typically lies in one of the following issues:

Incorrect Foreign Key Reference

Confirm that the primary key field referenced by the foreign key in the sira_no table exists in the referenced table (metal_kod) with matching data types and constraints. Incorrect field types or inconsistencies can lead to this error message.

Missing Index on Referenced Field

If the referenced field in the metal_kod table does not have an index, creating one can resolve the issue. An index allows for faster lookups and ensures efficient data access.

Charset and Collation Mismatch

Verify that the character set and collation settings of the METAL_KODU field in both the sira_no and metal_kod tables are identical. Differences in these settings can prevent proper data comparison and foreign key establishment.

Other Potential Causes

Consider the following additional factors that may contribute to this error:

• Duplicate foreign key names
• Mismatched key field sizes or types
• MyISAM table format (InnoDB is required for foreign key constraints)
• Cascade constraints with NOT NULL fields
• Default values on foreign key columns
• Missing individual indexes on combination key fields
• Syntax errors in the ALTER statement
• Excessive foreign key name length

To resolve this issue effectively, it is crucial to仔细检查 the underlying relationship definitions, ensure proper indexing, verify data type compatibility, and address any other potential causes.

The above is the detailed content of Error Code 1005: Why Can't I Create This Table and How Do I Fix It?. For more information, please follow other related articles on the PHP Chinese website!