T-SQL string replace in Update

Question

I need to update the values of a column, with a substring replace being done on the existing values.

Example:

Data contains abc@domain1, pqr@domain2 etc.

I need to update the values such that @domain2 is replaced with @domain1.

Solution 1

The syntax for REPLACE:

REPLACE (string_expression,string_pattern,string_replacement)

So that the SQL you need should be:

UPDATE [DataTable] SET [ColumnValue] = REPLACE([ColumnValue], 'domain2', 'domain1')

Solution 2

If anyone cares, for NTEXT, use the following format:

SELECT CAST(REPLACE(CAST([ColumnValue] AS NVARCHAR(MAX)),'find','replace') AS NTEXT) 
    FROM [DataTable]

Solution 3

update YourTable
    set YourColumn = replace(YourColumn, '@domain2', '@domain1')
    where charindex('@domain2', YourColumn) <> 0

Comments

[deniz]

Does including the where clause as in this answer provide any efficiency gains over the accepted answer?

[Adam Hey]

That statement in itself doesn't execute the update. you need to do the following: UPDATE [DataTable] SET SET [ColumnValue] = CAST(REPLACE(CAST([ColumnValue] AS NVARCHAR(MAX)),'domain2','domain1') AS NTEXT) FROM [DataTable]

[Daniel Butler]

In my case I needed to replace a double quote with a single quote. I used the following REPLACE([ColumnValue], '"', ''''). The end is four single quotes.