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LTRIM (Transact-SQL)

  • Άρθρο

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

Returns a character string after truncating all leading spaces.

Removes space character char(32) or other specified characters from the start of a string.

Transact-SQL syntax conventions

Syntax

Syntax for SQL Server prior to SQL Server 2022 (16.x):

LTRIM ( character_expression )

Syntax for SQL Server 2022 (16.x) and later, Azure SQL Managed Instance, Azure SQL Database, Azure Synapse Analytics, and Microsoft Fabric:

Important

You need your database compatibility level set to 160 to use the optional characters argument.

LTRIM ( character_expression , [ characters ] )

Arguments

character_expression

An expression of character or binary data. character_expression can be a constant, variable, or column. character_expression must be of a data type, except text, ntext, and image, that is implicitly convertible to varchar. Otherwise, use CAST to explicitly convert character_expression.

characters

A literal, variable, or function call of any non-LOB character type (nvarchar, varchar, nchar, or char) containing characters that should be removed. nvarchar(max) and varchar(max) types aren't allowed.

Return types

Returns a character expression with a type of string argument where the space character char(32) or other specified characters are removed from the beginning of a character_expression. Returns NULL if input string is NULL.

Remarks

To enable the optional characters positional argument, enable database compatibility level 160 on the database that you connect to when executing queries.

Examples

A. Remove leading spaces

The following example uses LTRIM to remove leading spaces from a character expression.

SELECT LTRIM('     Five spaces are at the beginning of this string.');

Here's the result set.

---------------------------------------------------------------
  Five spaces are at the beginning of this string.

B: Remove leading spaces using a variable

The following example uses LTRIM to remove leading spaces from a character variable.

DECLARE @string_to_trim VARCHAR(60);
SET @string_to_trim = '     Five spaces are at the beginning of this string.';
SELECT
    @string_to_trim AS 'Original string',
    LTRIM(@string_to_trim) AS 'Without spaces';
GO

Here's the result set.

Original string                                            Without spaces
-----------------------------------------------------   ---------------------------------------------
     Five spaces are at the beginning of this string.    Five spaces are at the beginning of this string.

C. Remove specified characters from the beginning of a string

Important

You need your database compatibility level set to 160 to use the optional characters argument.

The following example removes the characters 123 from the beginning of the 123abc. string.

SELECT LTRIM('123abc.' , '123.');

Here's the result set.

abc.

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