在整个表格中搜索单词-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

您可以执行以下操作：如果表结构发生更改，则需要从查询中添加/删除列。

SELECT * FROM myTable WHERE Concat(col1, '',col2, '', coln) LIKE '%searchKey%'