标签：param 二维 batch new 数组 target null 实现 dba
//批量删除
public void delBooks(String[] ids) throws SQLException {
QueryRunner qr = new QueryRunner(C3P0Utils.getDataSource());
Object[][] params = new Object[ids.length][];//高维确定执行sql语句的次数，低维是给？赋值
for (int i = 0; i < params.length; i++) {
params[i] = new Object[]{ids[i]};//给“？”赋值
}
qr.batch("delete from books where id=?", params);
}
源码实现：
public int[] batch(String sql, Object[][] params) throws SQLException { Connection conn = this.prepareConnection(); return this.batch(conn, true, sql, params); } private int[] batch(Connection conn, boolean closeConn, String sql, Object[][] params) throws SQLException { if (conn == null) { throw new SQLException("Null connection"); } if (sql == null) { if (closeConn) { close(conn); } throw new SQLException("Null SQL statement"); } if (params == null) { if (closeConn) { close(conn); } throw new SQLException("Null parameters. If parameters aren‘t need, pass an empty array."); } PreparedStatement stmt = null; int[] rows = null; try { stmt = this.prepareStatement(conn, sql); for (int i = 0; i < params.length; i++) { this.fillStatement(stmt, params[i]); stmt.addBatch(); } rows = stmt.executeBatch(); } catch (SQLException e) { this.rethrow(e, sql, (Object[])params); } finally { close(stmt); if (closeConn) { close(conn); } } return rows; }
解读: 因为params是一个二维数组, 所以往preparedStatement中赋值的时候使用了for循环, 然后通过preparedstatement.addBatch() 进行批量添加, 然后执行executeBatch()进行操作.
本文转自：https://www.cnblogs.com/wang-meng/p/5525389.html
关于DBUtils中QueryRunner看批量删除语句batch
标签：param 二维 batch new 数组 target null 实现 dba
原文地址：http://www.cnblogs.com/nizuimeiabc1/p/7875707.html
