How to Use the 'Like' Wildcard in Prepared Statements?

Using "like" Wildcard in Prepared Statements

Understanding the Issue

In database queries, the "like" wildcard is commonly used to search for data based on a keyword pattern. When using prepared statements to enhance query security and performance, it can be challenging to incorporate the "like" wildcard effectively.

Solution Using PreparedStatement

To use the "like" wildcard in a prepared statement, you do not modify the SQL string itself. Instead, set the "keyword%" within the value you set in the statement. Here's how to do it for different search types:

1. Prefix-Match:

   // Replace escape characters to prevent conflict with wildcard
   notes = notes
    .replace("!", "!!")
    .replace("%", "!%")
    .replace("_", "!_")
    .replace("[", "![");
   PreparedStatement pstmt = con.prepareStatement(
        "SELECT * FROM analysis WHERE notes LIKE ? ESCAPE '!'");
   pstmt.setString(1, notes + "%");

2. Suffix-Match:

   pstmt.setString(1, "%" + notes);

3. Global Match:

   pstmt.setString(1, "%" + notes + "%");

By setting the "keyword%" in the value assigned to the prepared statement, you can efficiently perform wildcard searches without compromising query security or performance.

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