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How to update a value in a column

Hi,

I have a table called Schedule and I would like to update a column called MyColumn. I want all strings that start with ABCD to be replaced by ZZZZ. I am using MS SQL Server. Can anybody help me do this?

Thanks

howyue

UPDATE Schedule SET MyColumn ='ZZZZ'
WHERE MyColumn LIKE 'ABCD%'

appari

Update Schedule
Set MyColumn = 'ZZZZ' + SubString(MyColumn , 5, datalength(MyColumn)-4)
where MyColumn like 'ABCD%'

appari

ignore my comment, I thought you want to replace the part ABCD with ZZZZ if the value starts with ABCD.

maloriopolium

ASKER

Sorry, what I meant was I want to keep the stuff after ABCD. For example: ABCD12345 becomes ZZZZ12345.

Thanks

howyue

UPDATE Schedule SET MyColumn =REPLACE(MyColumn, 'ABCD', 'ZZZZ')
WHERE MyColumn LIKE 'ABCD%'

maloriopolium

ASKER

Thanks howyue,
I have a problem. The column called MyColumn is actually called File
I get an error saying argument 1 of Replace function is not valid text? Any ideas

howyue

what is the datatype of ur [File] ?

UPDATE Schedule SET File =REPLACE(File , 'ABCD', 'ZZZZ')
WHERE File LIKE 'ABCD%'

maloriopolium

ASKER

The dat type is just text

SOLUTION

appari

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howyue

ur column is text, ok thats where the problem come from, REPLACE does not accept text as argument, however u can:

UPDATE Schedule SET [File] = REPLACE(CONVERT(VARCHAR(MAX), [File]), 'ABCD', 'ZZZZ')
WHERE Remarks LIKE 'ABCD%'

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howyue

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maloriopolium

ASKER

Ok, what I ended up doing was changing the datatype from text to varchar. Now it works.

Just out of curiosity. What is the difference between varchar and text and which should be used when?

Thanks

howyue

the essential different is that the maximum of their storage size. beside that, i'm not so sure. but in BOL microsoft suggests:

ntext, text, and image data types will be removed in a future version of Microsoft SQL Server. Avoid using these data types in new development work, and plan to modify applications that currently use them. Use nvarchar(max), varchar(max), and varbinary(max) instead. For more information, see Using Large-Value Data Types.

appari

and you better avoid replace, if you want to replace only the first occurance of ABCD.
replace will will replace all instances of ABCD in your text.

suppose your column has value "ABCDTest ABCD replace"
replace(yourCol,'ABCD', 'ZZZZ') will result "ZZZZTest ZZZZ replace"