Regular expression to find all table names in a query

Question

I am not that hot at regular expressions and it has made my little mind melt some what.

I am trying to find all the tables names in a query. So say I have the query

Answer 1

I used this code as an Excel macro to parse the select and extract table names.

My parsing assumes that the syntax select from a , b , c is not used.

Just run it against your SQL query and if you are not satisfied with the result you should be only a few lines of codes away from the result you expect. Just debug and modify the code accordingly.

Sub get_tables()
    sql_query = Cells(5, 1).Value
    tables = ""

    'get all tables after from
    sql_from = sql_query

    While InStr(1, UCase(sql_from), UCase("from")) > 0

        i = InStr(1, UCase(sql_from), UCase("from"))
        sql_from = Mid(sql_from, i + 5, Len(sql_from) - i - 5)
        i = InStr(1, UCase(sql_from), UCase(" "))

        While i = 1

            sql_from = Mid(sql_from, 2, Len(sql_from) - 1)
            i = InStr(1, UCase(sql_from), UCase(" "))

        end

        i = InStr(1, sql_join, Chr(9))

        While i = 1

            sql_join = Mid(sql_join, 2, Len(sql_join) - 1)
            i = InStr(1, sql_join, Chr(9))

        end

        a = InStr(1, UCase(sql_from), UCase(" "))
        b = InStr(1, sql_from, Chr(10))
        c = InStr(1, sql_from, Chr(13))
        d = InStr(1, sql_from, Chr(9))

        MinC = a

        If MinC > b And b > 0 Then MinC = b
        If MinC > c And c > 0 Then MinC = c
        If MinC > d And d > 0 Then MinC = d

        tables = tables + "[" + Mid(sql_from, 1, MinC - 1) + "]"

    end

    'get all tables after join
    sql_join = sql_query

    While InStr(1, UCase(sql_join), UCase("join")) > 0

        i = InStr(1, UCase(sql_join), UCase("join"))
        sql_join = Mid(sql_join, i + 5, Len(sql_join) - i - 5)
        i = InStr(1, UCase(sql_join), UCase(" "))

        While i = 1

            sql_join = Mid(sql_join, 2, Len(sql_join) - 1)
            i = InStr(1, UCase(sql_join), UCase(" "))

        end

        i = InStr(1, sql_join, Chr(9))

        While i = 1

            sql_join = Mid(sql_join, 2, Len(sql_join) - 1)
            i = InStr(1, sql_join, Chr(9))

        end

        a = InStr(1, UCase(sql_join), UCase(" "))
        b = InStr(1, sql_join, Chr(10))
        c = InStr(1, sql_join, Chr(13))
        d = InStr(1, sql_join, Chr(9))

        MinC = a

        If MinC > b And b > 0 Then MinC = b
        If MinC > c And c > 0 Then MinC = c
        If MinC > d And d > 0 Then MinC = d

        tables = tables + "[" + Mid(sql_join, 1, MinC - 1) + "]"

    end

    tables = Replace(tables, ")", "")
    tables = Replace(tables, "(", "")
    tables = Replace(tables, " ", "")
    tables = Replace(tables, Chr(10), "")
    tables = Replace(tables, Chr(13), "")
    tables = Replace(tables, Chr(9), "")
    tables = Replace(tables, "[]", "")

End Sub