Is SQL Server's LIKE Operator Case-Sensitive, and How Does Collation Affect It?

SQL Server's LIKE Operator: Case Sensitivity Explained

SQL Server's LIKE operator provides robust string matching. However, its case sensitivity isn't inherent to the operator itself. Instead, it's determined by the column's collation.

Collation: The Key to Case Sensitivity

A column's collation dictates how character comparisons are handled. SQL Server supports various collations, each specifying the character set, alphabet, and crucially, case-sensitivity rules.

Determining Collation

To check a database's collation:

SELECT DATABASEPROPERTYEX('databasename', 'collation') AS SQLCollation;

For a specific column:

SELECT COLLATION_NAME
FROM sys.columns
WHERE object_id = OBJECT_ID('TableName') AND name = 'ColumnName';

Collation's Impact on LIKE Results

Different collations produce different LIKE results. For example:

• sql_latin1_general_cp1_ci_as: Case-insensitive, accent-sensitive.
• sql_latin1_general_cp1_cs_as: Case-sensitive, accent-sensitive.

Modifying Collation (Use with Caution)

While generally discouraged, you can alter a column's collation:

ALTER TABLE TableName ALTER COLUMN ColumnName VARCHAR(10) COLLATE new_collation;

Alternatively, you can temporarily override case sensitivity within a query (not recommended for production):

SELECT column1 COLLATE sql_latin1_general_cp1_ci_as AS column1
FROM table1;

In Summary

Accurate string matching with SQL Server's LIKE operator hinges on understanding the impact of collation. Careful collation selection ensures queries behave as expected, regardless of case sensitivity requirements.

The above is the detailed content of Is SQL Server's LIKE Operator Case-Sensitive, and How Does Collation Affect It?. For more information, please follow other related articles on the PHP Chinese website!