自定义扩展函数，生成SQL错误返回

SqlSugar 老数据

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public static List<SqlFuncExternal> ExpMethods = new List<SqlFuncExternal>

{

new SqlFuncExternal()

{

UniqueMethodName = "SqlServerJsonContains",

MethodValue = (expInfo, dbType, expContext) =>

{

var value = string.Empty;

switch (dbType)

{

case DbType.SqlServer:

value = string.Format("(EXISTS(SELECT * FROM OPENJSON({0}) WHERE value = {1} AND {2}={2}))"

, expInfo.Args[0].MemberName

, expInfo.Args[2].MemberValue

, expInfo.Args[1].MemberName);

return value ;

default:

throw new Exception("未实现");

}

};

public static String SqlServerJsonContains(object json, object key, object value)

{

//这里不能写任何实现代码，需要在上面的配置中实现

throw new NotSupportedException("Can only be used in expressions");

}

调用后，生成的sql语句会加上一个（.）

SELECT * FROM [table] [gs]. WHERE (( [gs].[GoodsID] = [g].[GoodsID] )

AND EXISTS(SELECT * FROM OPENJSON([gs].[GoodsTypeID]) WHERE value = 4 AND gs.GoodsSpecID=gs.GoodsSpecID))

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