REPLICATE (Transact-SQL)

บทความ
09/03/2024

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

Repeats a string value a specified number of times.

Transact-SQL syntax conventions

Syntax

REPLICATE ( string_expression , integer_expression )

Arguments

string_expression
Is an expression of a character string or binary data type.

Note

If string_expression is of type binary, REPLICATE will perform an implicit conversion to varchar, and therefore will not preserve the binary input.

Note

If string_expression input is not of type varchar(max) or nvarchar(max), REPLICATE truncates the return value at 8,000 bytes. To return values greater than 8,000 bytes, string_expression must be explicitly cast to the appropriate large-value data type.

integer_expression
Is an expression of any integer type, including bigint. If integer_expression is negative, NULL is returned.

Return Types

Returns the same type as string_expression.

Examples

A. Using REPLICATE

The following example replicates a 0 character four times in front of a production line code in the AdventureWorks2022 database.

SELECT [Name]  
, REPLICATE('0', 4) + [ProductLine] AS 'Line Code'  
FROM [Production].[Product]  
WHERE [ProductLine] = 'T'  
ORDER BY [Name];  
GO

Here's the result set.

Name                                               Line Code  
-------------------------------------------------- ---------  
HL Touring Frame - Blue, 46                        0000T   
HL Touring Frame - Blue, 50                        0000T   
HL Touring Frame - Blue, 54                        0000T   
HL Touring Frame - Blue, 60                        0000T   
HL Touring Frame - Yellow, 46                      0000T   
HL Touring Frame - Yellow, 50                      0000T  
...

B. Using REPLICATE and DATALENGTH

The following example left pads numbers to a specified length as they are converted from a numeric data type to character or Unicode.

IF EXISTS(SELECT name FROM sys.tables  
      WHERE name = 't1')  
   DROP TABLE t1;  
GO  
CREATE TABLE t1   
(  
 c1 varchar(3),  
 c2 char(3)  
);  
GO  
INSERT INTO t1 VALUES ('2', '2'), ('37', '37'),('597', '597');  
GO  
SELECT REPLICATE('0', 3 - DATALENGTH(c1)) + c1 AS 'Varchar Column',  
       REPLICATE('0', 3 - DATALENGTH(c2)) + c2 AS 'Char Column'  
FROM t1;  
GO

Here's the result set.

  
Varchar Column        Char Column  
--------------------  ------------  
002                   2    
037                   37   
597                   597  
  
(3 row(s) affected)

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

C: Using REPLICATE

The following example replicates a 0 character four times in front of an ItemCode value.

-- Uses AdventureWorks  
  
SELECT EnglishProductName AS Name,  
   ProductAlternateKey AS ItemCode,  
   REPLICATE('0', 4) + ProductAlternateKey AS FullItemCode  
FROM dbo.DimProduct  
ORDER BY Name;

Here are the first rows in the result set.

Name                     ItemCode       FullItemCode
------------------------ -------------- ---------------
Adjustable Race          AR-5381        0000AR-5381
All-Purpose Bike Stand   ST-1401        0000ST-1401
AWC Logo Cap             CA-1098        0000CA-1098
AWC Logo Cap             CA-1098        0000CA-1098
AWC Logo Cap             CA-1098        0000CA-1098
BB Ball Bearing          BE-2349        0000BE-2349

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