java調(diào)用mysql數(shù)據(jù)的方法:首先定義一個過程,獲取users表總記錄數(shù),將10設(shè)置到變量count中;然后修改mysql語句的結(jié)果符;接著將結(jié)果覆給變量a;最后顯示變量a的值。
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java調(diào)用mysql數(shù)據(jù)的方法:
過程
定義一個過程,獲取users表總記錄數(shù),將10設(shè)置到變量count中
create procedure simpleproc(out count int) begin select count(id) into count from users; end
修改mysql語句的結(jié)果符為;
mysql > delimiter ;
調(diào)用過程,將結(jié)果覆給變量a,@是定義變量的符號
call simpleproc(@a);
顯示變量a的值
select @a;
以下是Java調(diào)用Mysql的過程
String sql = "{call simpleproc(?)}"; Connection conn = JdbcUtil.getConnection(); CallableStatement cstmt = conn.prepareCall(sql); cstmt.registerOutParameter(1,Types.INTEGER); cstmt.execute(); Integer count = cstmt.getInt(1); System.out.println("共有" + count + "人");
函數(shù)
修改mysql語句的結(jié)果符為
mysql > delimiter
定義一個函數(shù),完成字符串拼接
create function hello( s char(20) ) returns char(50) return concat('hello,',s,'!');
修改mysql語句的結(jié)果符為;
mysql > delimiter ;
調(diào)用函數(shù)
select hello('world');
以下是Java調(diào)用Mysql的函數(shù)
String sql = "{? = call hello(?)}"; Connection conn = JdbcUtil.getConnection(); CallableStatement cstmt = conn.prepareCall(sql); cstmt.registerOutParameter(1,Types.VARCHAR); cstmt.setString(2,"zhaojun"); cstmt.execute(); String value = cstmt.getString(1); System.out.println(value); JdbcUtil.close(cstmt); JdbcUtil.close(conn);
想了解