npm install lifekit-mysqlhelper#mysql数据库帮助类
在mysql基础上的一层封装类，对于简单的数据库操作（单表增删改查、sql文件）提供简便的方法
#方法及使用
说明：主要用于sql的拼接，可以根据传入某些特定参数拼接出一条完整的sql,并且提供了加载sql.xml文件并取出对应配置的sql的功能
方法：
(1)、初始化工具类
``javascript`
var sqlparser = require("mysqlhelper").Sqlparser;
(2)、根据表名称查询数据库所有数据
`javascript
var sql = sqlparser.queryAll("tablename");
//=>select * from tablename
`
(3)、根据主键查询数据
`javascript
var sql = sqlparser.queryWithKey("tablename","GUID_","g0001");
//=>select * from tablename where GUID_='g0001'
`
(4)、根据表的某个字段查询值
`javascript
var sql = sqlparser.queryWithColumn("tablename","NAME","小杰");
//=>select * from tablename where NAME='小杰'
`
(5)、根据多个字段组成的json对象查询符合条件的数据
`javascript
var columnobj = {'name':'小杰','age':18};
var sql = sqlparser.queryWithColumns("tablename",columnobj);
//=>select * from tablename where name='小杰' and age='18'
`
(6)、根据一个字符串组成的where条件查询符合条件的数据
`javascript
var where = "name='小杰' and age='18'";
var sql = sqlparser.queryWithWhere("tablename",where);
//=>select * from tablename where name='小杰' and age='18'
`
(7)、根据表名称插入单行数据
`javascript
var arr = ["G0001","小杰",18];
var sql = sqlparser.insertRow("tablename",arr);
//=>insert into tablename values('G0001','小杰','18');
`
(8)、根据表名称按字段插入一行数据
`javascript
var columns = ["GUID","NAME","AGE"];
var values = ["G0001","小杰",18];
var sql = sqlparser.insertColumnForArray("tablename",columns,values);
//=>insert into tablename (GUID,NAME,AGE) values ("G0001","小杰",18)
`
(9)、根据表名称按json对象插入数据
`javascript
var json = {"GUID":"G0001","NAME":"小杰","AGE":18};
var sql = sqlparser.insertColumnForJson(tablename,json);
//=>insert into tablename (GUID,NAME,AGE) values ("G0001","小杰",18)
`
(10)、根据表名称和主键更新字段
`javascript
var setobjs = {"NAME":"小杰","AGE":18};
var sql = sqlparser.updateObjForKey("tablename",setobjs,"GUID","G0001");
//=>update tablename set NAME='小杰',AGE=18 where GUID='G0001'
`
(11)、根据表名称和主键更新字段
`javascript
var setcolumns=["AGE","SEX"];
var setvalues=[18,"男"];
var sql = sqlparser.updateArrayForKey("tablename",setcolumns,setvalues,"NAME","小杰");
//=>update tablename set AGE='18',SEX='男' where NAME='小杰'
`
(12)、根据表名称与字段数组更新对应表的字段信息
`javascript
var setcolumns = ["AGE","SEX"];
var setvalues = [18,"男"];
var wherecolumns = ["GUID","NAME"];
var wherevalues = ["G00001","小杰"];
var sql = sqlparser.updateForArray("tablename",setcolumns,setvalues,wherecolumns,wherevalues);
//=>update tablename set AGE='18',SEX='男' where GUID='G00001' and NAME='小杰'
`
(13)、根据表名称与字段对象更新对应表的字段信息
`javascript
var setobjs = {"AGE":18,"SEX":"男"};
var whereobjs = {"GUID":"G00001","NAME":"小杰"};
var sql = sqlparser.updateForJson("tablename",setobjs,whereobjs);
//=>update tablename set AGE='18',SEX='男' where GUID='G00001' and NAME='小杰'
`
(14)、根据表名称和字段删除指定行
`javascript
var sql = sqlparser.delete("tablename","NAME","小杰");
//=>delete from tablename where NAME='小杰'
`
(15)、根据表名称和主键删除行
`javascript
var sql = sqlparser.deleteForKey("tablename","GUID","G00001");
//=>delete from tablename where GUID='G00001'
`
(16)、根据表名和字段数组删除指定数据
`javascript
var keys=["GUID","NAME"];
var key_values = ["G00001","小杰"];
var sql = sqlparser.deleteForArray("tablename",keys,key_values);
//=>delete from tablename where GUID='G00001' and NAME='小杰'
`
(17)、根据表名和字段对象删除指定数据
`javascript
var columnObjs = {"GUID":"G00001","NAME":"小杰"};
var sql = sqlparser.deleteForJson("tablename",columnObjs);
//=>delete from tablename where GUID='G00001' and NAME='小杰'
`
(18)、删除表的所有数据
`javascript
var sql = sqlparser.deleteAll("tablename");
//=>delete from tablename
`
(19)、加载数据文件，根据sqlId取出对应的sql(这里需要注意，这个方法是异步方法，区别于原物联网平台)
`javascript
sqlparser.loadSqlFile(__filename,function(sqlProperty){
var sqlId='C60B9A90B8154AF3863C7E2CCED0FF68',
mapkeys = new map(),
parms = [];
var sql = sqlparser.getSql(sqlProperty,sqlId,mapkeys,parms);
});
`
对应的xml文件同原物联网平台相同,例子：
`xml
`
##dbhelper工具类
说明：主要提供执行SQL的方法,自行管理数据库连接,此类提供一个全局变量dbhelper
方法：
(1)、初始化工具类
`javascript`
require("mysqlhelper").dbhelper("iot","192.168.1.212",3306,"iot","iot");
初始化之后就会有一个全局变量global.dbhelper产生
(2)、根据传入的sql查询结果集
`javascript`
var sql = "select * from table";
global.dbhelper.execDataSet(sql,function(err,rows){
});
(3)、根据传入的sql操作数据库（增删改）
`javascript
var sql = "update table set name='小杰' where guid='ga001'";
global.dbhelper.execNonQuery(sql,function(err,rows){
});
``