search for a word in entire table - MySQL - mysql

Question

Currently am using the following code for search for a word in the entire table,
Dim searchKey As String = "Sample"
Dim mysql As String = "SELECT * FROM myTable " & _
"WHERE col1 LIKE '%" & searchKey & "%' " & _
" OR col2 LIKE '%" & searchKey & "%' " & _
" OR col3 LIKE '%" & searchKey & "%' " & _
" OR col4 LIKE '%" & searchKey & "%' "
But querying became more difficult when the number of column increases. so can anyone suggest me some alternative method for do the same.

Answer 1

use a loop to build your String programmatically .in this example you only need to add your columns to array.
Dim searchKey As String = "Sample"
Dim array() As String = {"col1", "col2", "col3", "col4"}
Dim b As Boolean = True
Dim mysql As String = "SELECT * FROM myTable WHERE "
For Each str As String In array
If b Then
mysql = mysql & str + " LIKE '%" & searchKey & "%'"
Else
mysql = mysql & " OR " & str & " LIKE '%" & searchKey & "%'"
End If
b = False
Next
Debug.WriteLine(mysql)
output>>
SELECT * FROM myTable WHERE col1 LIKE '%Sample%' OR col2 LIKE '%Sample%' OR col3 LIKE '%Sample%' OR col4 LIKE '%Sample%'

Answer 2

You can also take help of the fulltext search provided by MySQL.
This link provides details on fulltext search, http://dev.mysql.com/doc/refman/5.0/en/fulltext-natural-language.html

Answer 3

You can do something like this, If there is change in table structure then you need to add/remove columns from the query.
SELECT * FROM myTable WHERE Concat(col1, '',col2, '', coln) LIKE '%searchKey%'