• JDBC的批处理操作三种方式


    SQL批处理是JDBC性能优化的重要武器,经本人研究总结,批处理的用法有三种。
     
    package lavasoft.jdbctest; 

    import lavasoft.common.DBToolkit; 

    import java.sql.Connection; 
    import java.sql.PreparedStatement; 
    import java.sql.SQLException; 
    import java.sql.Statement; 

    /** 
    * JDBC的批量操作三种方式 

    * @author leizhimin 2009-12-4 14:42:11 
    */
     
    public class BatchExeSQLTest { 

            public static void main(String[] args) { 
                    exeBatchStaticSQL(); 
            } 

            /** 
             * 批量执行预定义模式的SQL 
             */
     
            public static void exeBatchParparedSQL() { 
                    Connection conn = null
                    try { 
                            conn = DBToolkit.getConnection(); 
                            String sql = "insert into testdb.book (kind, name) values (?,?)"
                            PreparedStatement pstmt = conn.prepareStatement(sql); 
                            pstmt.setString(1, "java"); 
                            pstmt.setString(2, "jjjj"); 
                            pstmt.addBatch();                     //添加一次预定义参数 
                            pstmt.setString(1, "ccc"); 
                            pstmt.setString(2, "dddd"); 
                            pstmt.addBatch();                     //再添加一次预定义参数 
                            //批量执行预定义SQL 
                            pstmt.executeBatch(); 
                    } catch (SQLException e) { 
                            e.printStackTrace(); 
                    } finally { 
                            DBToolkit.closeConnection(conn); 
                    } 
            } 

            /** 
             * 批量执行混合模式的SQL、有预定义的,还有静态的 
             */
     
            public static void exeBatchMixedSQL() { 
                    Connection conn = null
                    try { 
                            conn = DBToolkit.getConnection(); 
                            String sql = "insert into testdb.book (kind, name) values (?,?)"
                            PreparedStatement pstmt = conn.prepareStatement(sql); 
                            pstmt.setString(1, "java"); 
                            pstmt.setString(2, "jjjj"); 
                            pstmt.addBatch();    //添加一次预定义参数 
                            pstmt.setString(1, "ccc"); 
                            pstmt.setString(2, "dddd"); 
                            pstmt.addBatch();    //再添加一次预定义参数 
                            //添加一次静态SQL 
                            pstmt.addBatch("update testdb.book set kind = 'JAVA' where kind='java'"); 
                            //批量执行预定义SQL 
                            pstmt.executeBatch(); 
                    } catch (SQLException e) { 
                            e.printStackTrace(); 
                    } finally { 
                            DBToolkit.closeConnection(conn); 
                    } 
            } 

            /** 
             * 执行批量静态的SQL 
             */
     
            public static void exeBatchStaticSQL() { 
                    Connection conn = null
                    try { 
                            conn = DBToolkit.getConnection(); 
                            Statement stmt = conn.createStatement(); 
                            //连续添加多条静态SQL 
                            stmt.addBatch("insert into testdb.book (kind, name) values ('java', 'java in aciton')"); 
                            stmt.addBatch("insert into testdb.book (kind, name) values ('c', 'c in aciton')"); 
                            stmt.addBatch("delete from testdb.book where kind ='C#'"); 
                            stmt.addBatch("update testdb.book set kind = 'JAVA' where kind='java'"); 
    //                        stmt.addBatch("select count(*) from testdb.book");                //批量执行不支持Select语句 
                            //执行批量执行 
                            stmt.executeBatch(); 
                    } catch (SQLException e) { 
                            e.printStackTrace(); 
                    } finally { 
                            DBToolkit.closeConnection(conn); 
                    } 
            } 
    }
     
    注意:JDBC的批处理不能加入select语句,否则会抛异常:
    java.sql.BatchUpdateException: Can not issue SELECT via executeUpdate(). 
      at com.mysql.jdbc.StatementImpl.executeBatch(StatementImpl.java:1007)
     

    本文出自 “熔 岩” 博客,请务必保留此出处http://lavasoft.blog.51cto.com/62575/238651

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  • 原文地址:https://www.cnblogs.com/azhqiang/p/4038390.html
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