Collation Functions - TERTIARY_WEIGHTS (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)

For each character in a non-Unicode string expression - defined with a SQL tertiary collation - this function returns a binary string of weights.

Transact-SQL syntax conventions

TERTIARY_WEIGHTS( non_Unicode_character_string_expression )  

non_Unicode_character_string_expression
A string expression of type char, varchar, or varchar(max) defined on a tertiary SQL collation. For a list of these collations, see Remarks.

TERTIARY_WEIGHTS returns varbinary when non_Unicode_character_string_expression is char or varchar, and it returns varbinary(max) when the non_Unicode_character_string_expression has a varchar(max) data type.

TERTIARY_WEIGHTS returns NULL when a SQL tertiary collection does not define the non_Unicode_character_string_expression. This table shows the SQL tertiary collations:

Use TERTIARY_WEIGHTS for the definition of a computed column defined on the values of a char, varchar, or varchar(max) column. Index definition on both the computed column and the char, varchar, or varchar(max) column can improve performance when the ORDER BY clause of a query specifies that char, varchar, or varchar(max) column.

This example creates a computed column in a table that applies the TERTIARY_WEIGHTS function to the values of a char column:

CREATE TABLE TertColTable  
(Col1 char(15) COLLATE SQL_Latin1_General_Pref_CP437_CI_AS,  
Col2 AS TERTIARY_WEIGHTS(Col1));  
GO   

ORDER BY Clause (Transact-SQL)