SQL search all columns of a table for text value

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后悔当初
后悔当初 2021-01-16 02:20

I have a huge table with many columns and I know that this columns sometimes takes some specific value \'MyValue\'. How can I select all the rows in that one specific table

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  • 2021-01-16 02:43

    You can do this by reversing the value and column in In operator.

    SELECT *
    FROM   Mytable
    WHERE  'Myvalue' IN ( Col1, Col2, col3,.... ) 
    

    If you don't want to type the columns, then pull it from information_schema.column view and create a dynamic query

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  • 2021-01-16 02:49

    You can concatenate all columns with + and then perform a LIKE search:

    SELECT *
    FROM   data
    WHERE  col1 + '#' + col2 + '#' + col3 like '%test%'
    

    Adding a separator (I use #) between the columns ensures you won't get false positives from the concatenation, e.g. if col2 = 'te' and col3 = 'st'

    SQL Fiddle

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  • 2021-01-16 02:50

    To do it without a special procedure in a simple statement, you could convert each row to XML and then use an XQuery on the XML to search for any value in the row that matches. So for example:

    declare @SearchValue as varchar(20)
    set @SearchValue = 'MyValue'
    
    select *
        --,(select MyTable.* for XML PATH (''),TYPE) AllColumns
        --,convert(nvarchar(255),(select MyTable.* for XML PATH (''),TYPE).query('for $item in * where $item=sql:variable("@SearchValue") return $item')) FoundColumns
    from MyTable
    where convert(nvarchar(255),(select MyTable.* for XML PATH (''),TYPE).query('for $item in * where $item=sql:variable("@SearchValue") return $item'))<>''
    

    A procedure specifically designed for this task could probably do this more efficiently and could take advantage of indexes... etc. Honestly I would not put this into a production database solution without quite a bit of consideration, but as a throw together search tool it's not bad. I ran a search on a 700,000 record table in 40 seconds. However if I filter by each column individually it runs nearly instantly. Also a few more caveats:

    • None of the table columns can not have spaces or other unfriendly characters for an XML tag. I couldn't figure out how to get column names with spaces to work. Maybe there's a way.
    • The filter has to be written in XQuery... which is not exactly like SQL. But you can use =, <, >, and there's even pattern matching.
    • The parameter for the query function must be a string literal. So you can't build a string dynamically. This is why I used the variable for your search values, but you could also use a sql:column("ColName") if needed.
    • If searching for other types besides strings, the search string you use must match exactly what the field would be converted to as an XML value.
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