C# 在mysql中将DAL函数转换为存储过程
嗨,我的数据访问层有一个类,它包含一个名为C# 在mysql中将DAL函数转换为存储过程,c#,mysql,stored-procedures,data-access-layer,C#,Mysql,Stored Procedures,Data Access Layer,嗨,我的数据访问层有一个类,它包含一个名为GetCitiesByLocation的函数 public DataTable GetCitiesByLocation(long pStateID, string pKeyword) { //create database object Database db = DBHelper.CreateDatabase(); //create SELECT sql statement to be executed using stri
GetCitiesByLocation
的函数
public DataTable GetCitiesByLocation(long pStateID, string pKeyword)
{
//create database object
Database db = DBHelper.CreateDatabase();
//create SELECT sql statement to be executed using string builder
//add WHERE 1 = 1 at the end
//add where [optional] statements
if (String.IsNullOrEmpty(pKeyword) == false)
{
//Create AND statement for ?Keyword
}
//add group by order by queries
sql.Append(" GROUP BY c.city_id ");
sql.Append(" ORDER BY city_name ");
//Convert SQL String To DbCommand Object
DbCommand comm = db.GetSqlStringCommand(sql.ToString());
//Map Variables to mysql ?Parameters
db.AddInParameter(comm, "?StateID", DbType.Int64, pStateID);
db.AddInParameter(comm, "?Keyword", DbType.String, pKeyword);
try
{
//execute sql statement and return results
}
catch (Exception ex)
{
throw ex;
}
}
请参见此处的完整版本:
我想将其转换为MYSQL存储过程
下面是我的朋友将其转换为MSSQL存储过程的失败尝试
ALTER PROCEDURE [dbo].[sp_Search]
@Keyword varchar(30)
AS
SELECT count(cc.course_id) as 'course_count', c.*, con.* FROM city c
LEFT JOIN countries con on con.country_id = c.country_id
LEFT JOIN courses cc on cc.city_id = c.city_id
WHERE 1 = 1
AND CASE @Keyword WHEN (@Keyword <> NULL) THEN (AND c.state_name like @Keyword) END
AND CASE @Keyword WHEN (pStateID > 0) THEN (AND c.state_id = @StateID AND c.country_id = 69 AND c.province_id = 0) END
AND CASE @Keyword WHEN (pProvinceID > 0) THEN (AND c.province_id = @ProvinceID AND c.country_id = 52 AND c.state_id = 0) END
ALTER过程[dbo].[sp_搜索]
@关键词varchar(30)
作为
从城市c中选择计数(抄送课程id)作为“课程计数”,c.*,con.*
在con.country\u id=c.country\u id上左连接国家con
左连接课程cc on cc.city\u id=c.city\u id
其中1=1
和CASE@Keyword WHEN(@Keyword NULL)然后(和c.state_name一样@Keyword)结束
和CASE@Keyword WHEN(pStateID>0),然后(c.state\u id=@StateID和c.country\u id=69和c.province\u id=0)结束
和CASE@Keyword WHEN(pProvinceID>0)则(c.ProvinceID=@ProvinceID和c.country\u id=52和c.state\u id=0)结束
我还有一个事务DAL,我想将其转换为mysql存储过程,我不是mysql方面的专家,但似乎您试图以执行参数化查询的方式执行存储过程,但这不起作用 如果你的MSSQL程序按照我预期的那样编译,我也会非常惊讶
ALTER PROCEDURE [dbo].[sp_Search]
@Keyword varchar(30),
@StateID int = null,
@ProvinceID int = null
或者在MySQL中
CREATE PROCEDURE sp_Search(Keyword varhar(30),
StateID int,
ProviceId int)
您最希望通过以下方式更改DAL
您好,我知道如何访问存储过程,存储过程示例中的参数被故意截断,只是为了表示我想要的示例输出。我想将我现有的DAL代码转换成一个存储过程,DAL包含一系列if语句。