java.sql.SQLException : Parameter number X is not an OUT parameter 异常

Question

我正在努力从 MySQL 存储过程中获取结果 OUT 变量。我收到以下错误:

java.sql.SQLException: Parameter number 3 is not an OUT parameter

存储过程如下所示:

CREATE DEFINER=`cv_admin`@`localhost` PROCEDURE `CheckGameEligibility`(
   IN gID INT(10),
   IN uID INT(10),

   OUT result TINYINT(1)
)
BEGIN
    # Do lots of stuff, then eventually:
    SET result = 1;
END 

我的 java 函数采用字符串数组* 并动态创建 CallableStatement 对象:

public static int callAndReturnResult( String sql , String[] values )
{
    int out = 0 ;
    try
    {
        // construct the SQL. Creates: CheckGameEligibility(?, ?, ?)
        sql += "(" ;

        for( int i = 0 ; i < values.length ; i++ )
        {
            sql += "?, " ;
        }
        sql += "?)" ;

        System.out.println( "callAndReturnResult("+sql+"): constructed SQL: " + sql );

        // Then the statement
        CallableStatement cstmt = DB.prepareCall( sql );
        for( int i = 0 ; i < values.length ; i++ )
        {
            System.out.println( "   " + (i+1) + ": " + values[ i ] ) ;
            cstmt.setString(i+1, values[ i ] );
        }

        System.out.println( "   " + (values.length+1) + ": ? (OUT)" ) ;
        cstmt.registerOutParameter( values.length + 1 , Types.TINYINT );
        cstmt.execute();

        out = cstmt.getInt( values.length );
        cstmt.close();
    }
    catch( Exception e )
    {
        System.out.println( "*** db trouble: callAndReturnResult(" + sql + " failed: " + e );
        e.printStackTrace() ;
    }
    return out ;
}

*) 我想我应该使用 int 数组而不是字符串数组，但这似乎不是错误消息的内容。

无论如何，这是它生成的输出:

callAndReturnResult(CheckGameEligibility(?, ?, ?)): constructed SQL: CheckGameEligibility(?, ?, ?)
1: 57
2: 29
3: ? (OUT)
*** db trouble: callAndReturnResult(CheckGameEligibility(?, ?, ?) failed: java.sql.SQLException: Parameter number 3 is not an OUT parameter
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1075)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:929)
    at com.mysql.jdbc.CallableStatement.checkIsOutputParam(CallableStatement.java:692)
    at com.mysql.jdbc.CallableStatement.registerOutParameter(CallableStatement.java:1847)
    at org.apache.commons.dbcp.DelegatingCallableStatement.registerOutParameter(DelegatingCallabl>eStatement.java:92)
    at Tools.callAndReturnResult(Tools.java:156)

任何想法可能是什么问题？ :)

提前致谢!

Answer 1

我的代码略有不同

CallableStatement statement = connection.prepareCall("{? = call nextOperatorTransactionId()}");
statement.registerOutParameter(1, Types.BIGINT);
statement.execute();
id.set(statement.getLong(1));

注意括号，在我的例子中是？在句子的开头。不使用括号我得到了和你一样的异常