Can't insert byte[] into MySQL using java

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夕颜
夕颜 2021-01-13 08:59

Following is the code I have used:

byte[] bkey = key.getEncoded();
String query = \"INSERT INTO keytable (name, key) VALUES (?,?)\";
PreparedStatement pstmt          


        
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  • 2021-01-13 09:39

    The problem is that your column called "key" is a reserve word in SQL. Surround it with backticks and things should work. Better yet, consider renaming the column to something that is not a SQL reserve word. I've proven this out using the code below:

    MySQL table:

    create table keytable (name varchar(255) not null, `key` blob not null);
    

    Java code:

    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    import java.sql.SQLException;
    
    public class MySQLBlobInsert {
    
        public static void main(String[] args) {
            try {
                Class.forName("com.mysql.jdbc.Driver").newInstance();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
            Connection conn = null;
            try {
                conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");
                byte[] bkey = "This is some binary stuff".getBytes();
                String query = "INSERT INTO keytable (name, `key`) VALUES (?,?)";
                PreparedStatement pstmt = conn.prepareStatement(query);
                pstmt.setString(1, "test");
                pstmt.setBytes(2, bkey);
                pstmt.execute();
            } catch (SQLException e) {
                throw new RuntimeException(e);
            } finally {
                if (conn != null) {
                    try { conn.close(); } catch (SQLException e) {}
                }
            }
            System.out.println("done :)");
        }
    }
    
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  • 2021-01-13 09:39

    Try using "setBinaryStream()" instead of "setBytes()", and pass it a ByteArrayInputStream constructed on your byte array. This, of course, assumes that the data type assigned to the column can store bytes... Make sure it is a BLOB, BINARY, or VARBINARY.

    Also, use backticks to enclose your objects. "key" is a SQL keyword, and other than that it is just a good habit:

    String query = "INSERT INTO `keytable` (`name`, `key`) VALUES (?,?)";
    
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  • 2021-01-13 09:39

    You should add a binary stream. Do you have access to the inputstream ?? like this..

    FileInputStream input = new FileInputStream("myfile.gif");
    String query = "INSERT INTO `keytable` (`name`, `key`) VALUES (?,?)";
    PreparedStatement pstmt = (PreparedStatement) connection.prepareStatement(query);
    pstmt.setString(1, "test");
    pstmt.setBinaryStream(2, input, input.available());
    
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