jdbc mysql动态建表

Posted 2020-11-14 masterchd

通过检查来决定是否建表

如果表尚未被建立，就执行ptmt语句更新，在数据库中创建这个表，

如果这个表已经存在，就不执行建表操作了；

 

package SQLCon;
import java.sql.*;
public class CreateTables {
	public static boolean HaveTable(String TableName) throws ClassNotFoundException, SQLException {
		Class.forName("com.mysql.jdbc.Driver");
        String user = "root";
        String pwd = "123456";
        String url = "jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=utf-8&useSSL=false";
        Connection conn = DriverManager.getConnection(url, user, pwd);
        ResultSet rs = conn.getMetaData().getTables(null, null, TableName, null);
        if(rs.next()) {
        	rs.close();
        	conn.close();
        	return true;
        }else
        {
        	rs.close();
        	conn.close();
        	return false;
        }
	}
	public static void main(String args[]) throws SQLException, ClassNotFoundException {
		Class.forName("com.mysql.jdbc.Driver");
        String user = "root";
        String pwd = "123456";
        String url = "jdbc:mysql://localhost:3306/activiti?useUnicode=true&characterEncoding=utf-8&useSSL=false";
        Connection conn = DriverManager.getConnection(url, user, pwd);
        if(HaveTable("MyTables")!=true){
			String sql = "CREATE TABLE ACT_SHIP_USER "+
					"(ID_ VARCHAR(64) not NULL, " +
					"ORG_ VARCHAR(255), " +
					"JOB_ VARCHAR(255), "+
					"PRIMARY KEY (ID_))";
			PreparedStatement ptmt = conn.prepareStatement(sql);
			ptmt.executeUpdate(sql);
			ptmt.close();
		}
        else
        {
        	System.out.println("table is existed!");
        }
	}
}