如何在 MsSQL 中执行简单的“查找和替换”？

The following query replace each and every a character with a b character.

UPDATE
YourTable
SET
Column1 = REPLACE(Column1,'a','b')
WHERE
Column1 LIKE '%a%'

This will not work on SQL server 2003.

like so:

BEGIN TRANSACTION;
UPDATE table_name
SET column_name=REPLACE(column_name,'text_to_find','replace_with_this');
COMMIT TRANSACTION;

Example: Replaces <script... with <a ... to eliminate javascript vulnerabilities

BEGIN TRANSACTION; UPDATE testdb
SET title=REPLACE(title,'script','a'); COMMIT TRANSACTION;

If you are working with SQL Server 2005 or later there is also a CLR library available at http://www.sqlsharp.com/ that provides .NET implementations of string and RegEx functions which, depending on your volume and type of data may be easier to use and in some cases the .NET string manipulation functions can be more efficient than T-SQL ones.

This pointed me in the right direction, but I have a DB that originated in MSSQL 2000 and is still using the ntext data type for the column I was replacing on. When you try to run REPLACE on that type you get this error:

Argument data type ntext is invalid for argument 1 of replace function.

The simplest fix, if your column data fits within nvarchar, is to cast the column during replace. Borrowing the code from the accepted answer:

UPDATE YourTable
SET Column1 = REPLACE(cast(Column1 as nvarchar(max)),'a','b')
WHERE Column1 LIKE '%a%'

This worked perfectly for me. Thanks to this forum post I found for the fix. Hopefully this helps someone else!

The following will find and replace a string in every database (excluding system databases) on every table on the instance you are connected to:

Simply change 'Search String' to whatever you seek and 'Replace String' with whatever you want to replace it with.

--Getting all the databases and making a cursor
DECLARE db_cursor CURSOR FOR
SELECT name
FROM master.dbo.sysdatabases
WHERE name NOT IN ('master','model','msdb','tempdb')  -- exclude these databases


DECLARE @databaseName nvarchar(1000)
--opening the cursor to move over the databases in this instance
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO @databaseName


WHILE @@FETCH_STATUS = 0
BEGIN
PRINT @databaseName
--Setting up temp table for the results of our search
DECLARE @Results TABLE(TableName nvarchar(370), RealColumnName nvarchar(370), ColumnName nvarchar(370), ColumnValue nvarchar(3630))


SET NOCOUNT ON


DECLARE @SearchStr nvarchar(100), @ReplaceStr nvarchar(100), @SearchStr2 nvarchar(110)
SET @SearchStr = 'Search String'
SET @ReplaceStr = 'Replace String'
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')


DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128)
SET  @TableName = ''


--Looping over all the tables in the database
WHILE @TableName IS NOT NULL
BEGIN
DECLARE @SQL nvarchar(2000)
SET @ColumnName = ''
DECLARE @result NVARCHAR(256)
SET @SQL = 'USE ' + @databaseName + '
SELECT @result = MIN(QUOTENAME(TABLE_SCHEMA) + ''.'' + QUOTENAME(TABLE_NAME))
FROM    [' + @databaseName + '].INFORMATION_SCHEMA.TABLES
WHERE       TABLE_TYPE = ''BASE TABLE'' AND TABLE_CATALOG = ''' + @databaseName + '''
AND QUOTENAME(TABLE_SCHEMA) + ''.'' + QUOTENAME(TABLE_NAME) > ''' + @TableName + '''
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + ''.'' + QUOTENAME(TABLE_NAME)
), ''IsMSShipped''
) = 0'
EXEC master..sp_executesql @SQL, N'@result nvarchar(256) out', @result out


SET @TableName = @result
PRINT @TableName


WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
DECLARE @ColumnResult NVARCHAR(256)
SET @SQL = '
SELECT @ColumnResult = MIN(QUOTENAME(COLUMN_NAME))
FROM    [' + @databaseName + '].INFORMATION_SCHEMA.COLUMNS
WHERE       TABLE_SCHEMA    = PARSENAME(''[' + @databaseName + '].' + @TableName + ''', 2)
AND TABLE_NAME  = PARSENAME(''[' + @databaseName + '].' + @TableName + ''', 1)
AND DATA_TYPE IN (''char'', ''varchar'', ''nchar'', ''nvarchar'')
AND TABLE_CATALOG = ''' + @databaseName + '''
AND QUOTENAME(COLUMN_NAME) > ''' + @ColumnName + ''''
PRINT @SQL
EXEC master..sp_executesql @SQL, N'@ColumnResult nvarchar(256) out', @ColumnResult out
SET @ColumnName = @ColumnResult


PRINT @ColumnName


IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO @Results
EXEC
(
'USE ' + @databaseName + '
SELECT ''' + @TableName + ''',''' + @ColumnName + ''',''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630)
FROM ' + @TableName + ' (NOLOCK) ' +
' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
)
END
END
END


--Declaring another temporary table
DECLARE @time_to_update TABLE(TableName nvarchar(370), RealColumnName nvarchar(370))


INSERT INTO @time_to_update
SELECT TableName, RealColumnName FROM @Results GROUP BY TableName, RealColumnName


DECLARE @MyCursor CURSOR;
BEGIN
DECLARE @t nvarchar(370)
DECLARE @c nvarchar(370)
--Looping over the search results
SET @MyCursor = CURSOR FOR
SELECT TableName, RealColumnName FROM @time_to_update GROUP BY TableName, RealColumnName


--Getting my variables from the first item
OPEN @MyCursor
FETCH NEXT FROM @MyCursor
INTO @t, @c


WHILE @@FETCH_STATUS = 0
BEGIN
-- Updating the old values with the new value
DECLARE @sqlCommand varchar(1000)
SET @sqlCommand = '
USE ' + @databaseName + '
UPDATE [' + @databaseName + '].' + @t + ' SET ' + @c + ' = REPLACE(' + @c + ', ''' + @SearchStr + ''', ''' + @ReplaceStr + ''')
WHERE ' + @c + ' LIKE ''' + @SearchStr2 + ''''
PRINT @sqlCommand
BEGIN TRY
EXEC (@sqlCommand)
END TRY
BEGIN CATCH
PRINT ERROR_MESSAGE()
END CATCH


--Getting next row values
FETCH NEXT FROM @MyCursor
INTO @t, @c
END;


CLOSE @MyCursor ;
DEALLOCATE @MyCursor;
END;


DELETE FROM @time_to_update
DELETE FROM @Results


FETCH NEXT FROM db_cursor INTO @databaseName
END


CLOSE db_cursor
DEALLOCATE db_cursor

Note: this isn't ideal, nor is it optimized