Groovy笔记(9)_GroovySql
GroovySql概述
1、GSql结合利用闭包和迭代器，把资源管理的负担转移到Groovy框架本身，从而简化JDBC编程
2、不用关闭Conne，也不用关闭ResultSet
3、Groovy把迭代器编程隐含的，使用起来更简单。
def coll = ["groovy","grails","java"]
coll.each{tiem -> println item}
建库建表
1、创建MySQL数据库groovytoysstore
show databases;
create database groovysstore
character set utf8
2、建表toys,包含toyName，unitPrice 两列
use groovytoysstore
create table toys(toyName varchar(50) not null,
unitPrice varchar(20))
建立数据库连接
1、import groovy.sql.*
def db = 'jdbc:mysql: //主机/数据库
?useUnicode=true&characterEncoding=UTF-8'
def user = 'root'
def password = 'clat'
def driver = 'com.mysql.jdbc.Driver'
def sql = Sql.newInstahnce(db,user,password,driver)
// 需要把mysql的驱动jar包拷贝到项目lib目录下
数据库CRUD
1、sql.execute("delete from toys")
sql.execute("insert into toys values('toy1','100')")
sql.eachRow("select * from toys"){toy ->
println '/t/t'+toy.toyName + '/t' +toy.unitPrice}
2、def searchToyName = "toy1"
sql.eachRow("select * from toys where toyName =?",[searchToyName]){toy ->
println '/t/t' + toy.toyName +'/t' +toy.unitPrice}
3、def updateToyName = 'toy1'
def updateUnitPrice = '1000'
sql.execute("update toys set unitPrice= ? where toyName =? ",[updateUnitPrice,updateToyName])
操作DataSet(简化操作)
1、DataSet类是Sql类的子类（可以用Jad查看）
2、def toys = sql.dataSet('toys')
//dataSet()参数是表名
public DataSet dataSet(String tableName){
return new DataSet(this, talbe);
}
3、toys.add(toyName:'toy8',unitPrice:'800')
//public void add(Map values) throws SQLException
4、toys.each{toy ->
println toy.toyName + ':' + toy.unitPrice}
5、例子
def sql = Sql.newInstance(db,user,password,driver)
def toys = sql.dataSet('toys')
def list = toys.rows() //返回列表
println list.class
list.each{ //遍历列表
println it
}
def t = toys.firstRow() //获取第一行 ,lastRow()最后一行
println t
简单OR Mapping
1、SqlQuery抽象类（使用模板方法模式）
abstract class SqlQuery{
def sql ; def query
def SqlQuery(sql,query){
this.sql = sql; this.query = query
}
def abstract mapRow(row) //映射方法先定义，由子类实现
def execute(){
def rowsList = sql.rows(query)
def results = []
def size = rowsList.size()
0.upto(size - 1){ index ->
results << this.mapRow(rowsList[index])
}
return results
}
}
2、class ToyQuery extends SqlQuery{ //子类实现mapRow()方法
def ToyQuery(sql){
super(sql,'select * from toys')
}
def mapRow(row){
def acc = new Toy(toyName: row.getProperty("toyName"),
unitPrice: row.getProperty("unitPrice"))
return acc
}
}
3、使用上面的类 完成简单ORM , 数据库 -》 对象
def db = 'jdbc:mysql://localhost/groovytoysstore?useUnicode=true&characterEncoding=UTF-8'
def user= 'root'
def password = 'clat'
def driver = 'com.myql.jdbc.Driver'
def sql = Sql.newInstance(db,user,password,driver)
def toyQuery = new ToyQuery(sql)
def toys = toyQuery.execute()
toys.each{ toy -> println toy.toyName}