Connect to the database
Elementary rookie, temporarily configure the database in the routing for the convenience of the diagram, the connection pool is not used, the routing file
const mysql = require('mysql') //引入数据库插件
const koaRouter = require('koa-router');
const router = koaRouter();
//连接数据库
const connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '123456',
port: '3306',
database: 'testnode'
})
//新增数据
router.post('/add', async (ctx, next) => {
console.log(Boolean( ctx.request.query.name && ctx.request.query.address && ctx.request.query.phone))
if(ctx.request.query.phone && ctx.request.query.address && ctx.request.query.name){
var data = {
}
var createdTime=new Date()
var querySql="INSERT INTO address (createdTime,name,address,phone,belongsId) VALUES(?,?,?,?,?)"
var queryParams=[createdTime,ctx.request.query.name,ctx.request.query.address,ctx.request.query.phone,ctx.request.query.userId]
console.log(queryParams)
var searchSql = (querySql,queryParams) => {
return new Promise((resolve, reject) => {
console.log('准备查询')
connection.query(querySql,queryParams, function(err, result) {
if(err){
reject(0)
console.log(err+'err')
}
resolve(result)
})
})
}
var res= await searchSql(querySql,queryParams)
if(res){
data.code='0'
data.msg="添加成功"
ctx.body=data
}else{
data.code='1'
data.msg="添加失败"
ctx.body=data
}
}
});
//查询数据
router.get('/query', async (ctx, next) => {
var data = {
}
console.log(ctx.request.query.pageNo - 1)
var querySql="SELECT * FROM address where belongsId= '"+ctx.request.query.userId+"' limit "+ (ctx.request.query.pageNo-1)*ctx.request.query.pageSize+"," + ctx.request.query.pageSize
var querySqlNo="SELECT * FROM address where belongsId= '"+ctx.request.query.userId+"'"
var searchSql = (thesql) => {
return new Promise((resolve, reject) => {
console.log('准备查询')
connection.query(thesql, function(err, result) {
if(err){
reject(0)
console.log(err+'err')
}
resolve(result)
})
})
}
var res= await searchSql(querySqlNo)
if(res){
var datares= await searchSql(querySql)
if(datares){
var param={
list:datares,total:res.length}
data.code='0'
data.msg="成功获取"
data.data=param
ctx.body=data
}
}
})
//更新数据
router.post('/update', async (ctx, next) => {
var updateSql="UPDATE address SET name = '"+ctx.request.query.name+"', phone = '" + ctx.request.query.phone + "', address = '" + ctx.request.query.address +"' where id = '" +ctx.request.query.id + "'"
var searchSql = (thesql) => {
return new Promise((resolve, reject) => {
connection.query(thesql, function(err, result) {
if(err){
reject(1)
console.log(err+'err')
}
resolve(0)
})
})
}
var data={
}
var res= await searchSql(updateSql)
if(res==0){
data.msg="更新成功"
data.code=0
ctx.body=data
}else{
data.code=1
data.msg="更新失败,请稍后再试！"
ctx.body=data
}
});
//删除数据
router.post('/remove', async (ctx, next) => {
var deleteSql="DELETE FROM address WHERE "+"id='"+ctx.request.query.id + "'"
var searchSql = (thesql) => {
return new Promise((resolve, reject) => {
connection.query(thesql, function(err, result) {
if(err){
reject(1)
console.log(err+'err')
}
resolve(0)
})
})
}
var data={
}
var res= await searchSql(deleteSql)
if(res==0){
data.msg="删除成功"
data.code=0
ctx.body=data
}else{
data.code=1
data.msg="删除失败,请稍后再试！"
ctx.body=data
}
});
Highlights
- Splicing SQL operation statements
- Execute sql operation statement
- process result
Add, delete, modify and check sql statement
Add: INSERT INTO address (createdTime,name,address,phone,belongsId) VALUES(?,?,?,?,?)
var queryParams=[createdTime,ctx.request.query.name,ctx.request .query.address,ctx.request.query.phone,ctx.request.query.userId]
address is the query table name queryParams is the new data inserted corresponds to the above? You can also directly replace the question mark with the corresponding value.
Delete: "DELETE FROM address WHERE "+"id='11111"" id='11111' is the condition that meets the deletion.
address is the name of the query table. WHERE is the one that satisfies the deletion. Condition
change: "UPDATE address SET name ='"+ctx.request.query.name+"', phone ='" + ctx.request.query.phone + "', address ='" + ctx.request.query.address +"' where id ='" +ctx.request.query.id + "'"
address is the name of the query table. Between SET and where is the data to be inserted. After where is the id of the data to be inserted.
Check: SELECT * FROM address where belongsId='"+ctx.request.query.userId+"' limit “+ (ctx.request.query.pageNo-1)*ctx.request.query.pageSize+"," + ctx.request .query.pageSize
pageNo is the query page number pageSize is the number of the query belongsId="" is the query condition address is the query table name
The method of executing SQL statements can be packaged in a unified manner to reduce the amount of code
var searchSql = (thesql) => {
return new Promise((resolve, reject) => {
connection.query(thesql, function(err, result) {
if(err){
reject(1) //返回状态
console.log(err+'err')
}
resolve(0) //返回状态 //只有查询有具体返回内容
})
})
}