Trail: JDBC(TM) Database Access(3)

java.sql,javax.sql,javax.naming包 ? ?默认 TYPE_FORWARD_ONLY: 结果集只能向前滚动,只能调用next(),不能重定位游标 TYPE_SCROLL_INSENSITIVE, TYPE_SCROLL_SENSITIVE:可以重定位游标 TYPE_SCROLL_INSENSITIVE:底层修改不会反映到结果集 TYPE_SCROLL_SENSIT

java.sql,javax.sql,javax.naming包

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?默认TYPE_FORWARD_ONLY:结果集只能向前滚动,只能调用next(),不能重定位游标

TYPE_SCROLL_INSENSITIVE,TYPE_SCROLL_SENSITIVE:可以重定位游标

TYPE_SCROLL_INSENSITIVE:底层修改不会反映到结果集

TYPE_SCROLL_SENSITIVE:会实时显示真实数据

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默认CONCUR_READ_ONLY:不能更新到底层,只是读取

CONCUR_UPDATABLE:可以更新,可以写入

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stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,//可滚动,实时显示                   ResultSet.CONCUR_UPDATABLE);//可写入        ResultSet uprs = stmt.executeQuery(            "SELECT * FROM " + dbName + ".COFFEES");        while (uprs.next()) {            float f = uprs.getFloat("PRICE");            uprs.updateFloat( "PRICE", f * percentage);//设置某列            uprs.updateRow();//提交        }

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 stmt = con.createStatement(            ResultSet.TYPE_SCROLL_SENSITIVE            ResultSet.CONCUR_UPDATABLE);        ResultSet uprs = stmt.executeQuery(            "SELECT * FROM " + dbName +            ".COFFEES");        uprs.moveToInsertRow();//准备插入        uprs.updateString("COF_NAME", coffeeName);        uprs.updateInt("SUP_ID", supplierID);        uprs.updateFloat("PRICE", price);        uprs.updateInt("SALES", sales);        uprs.updateInt("TOTAL", total);        uprs.insertRow();//提交        uprs.beforeFirst();//游标不能再指向这里

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RowSet对象都是JavaBean组件

如果数据库不支持游标滚动,也不支持实时更新,可以用RowSet替代

RowSet有保持连接的和离线的两种

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public void createProcedureGetSupplierOfCoffee()    throws SQLException {    String createProcedure = null;    // ...    createProcedure =        "create procedure GET_SUPPLIER_OF_COFFEE(" +        "IN coffeeName varchar(32), " +//in        "OUT supplierName varchar(40)) " +//out        "begin " +            "select SUPPLIERS.SUP_NAME into " +            "supplierName " +            "from SUPPLIERS, COFFEES " +            "where SUPPLIERS.SUP_ID = " +            "COFFEES.SUP_ID " +            "and coffeeName = COFFEES.COF_NAME;<div style="color:transparent">本文来源gaodai.ma#com搞##代!^码@网*</div> " +            "select supplierName; " +        "end";    // ...}

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createProcedure =        "create procedure RAISE_PRICE(" +        "IN coffeeName varchar(32), " +        "IN maximumPercentage float, " +        "INOUT newPrice numeric(10,2)) " +//inout        "begin " +        "main: BEGIN " +            "declare maximumNewPrice " +                "numeric(10,2); " +            "declare oldPrice numeric(10,2); " +            "select COFFEES.PRICE into oldPrice " +...

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cs = this.con.prepareCall("{call GET_SUPPLIER_OF_COFFEE(?, ?)}");cs.setString(1, coffeeNameArg);cs.registerOutParameter(2, Types.VARCHAR);cs.executeQuery();String supplierName = cs.getString(2);

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cs = this.con.prepareCall("{call RAISE_PRICE(?,?,?)}");cs.setString(1, coffeeNameArg);cs.setFloat(2, maximumPercentageArg);cs.registerOutParameter(3, Types.NUMERIC);cs.setFloat(3, newPriceArg);cs.execute();Because the parameter newPrice (the third parameter in the procedure

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