private void TestEntityParam(TestValue v)
{
Expression <Func <CustomersEntity, bool> > queryExp1 = ct => ct.CustomerID <= v.Id && (SQLMethod.IsNull(ct.CustomerCity));
var translate = new SqlTranslateFormater();
string sql = translate.Translate(queryExp1);
Assert.Equal(sql, "CustomerID <= 50 AND CustomerCity is NULL");
}
public void SimpleWhereMethodTest2()
{
Expression <Func <CustomersEntity, bool> > queryExp1 = ct => ct.CustomerID <= 50 && (SQLMethod.IsNull(ct.CustomerCity));
var translate = new SqlTranslateFormater();
string sql = translate.Translate(queryExp1);
Assert.Equal(sql, "CustomerID <= 50 AND CustomerCity is NULL");
}
public void SimpleWhereTest1()
{
Expression <Func <CustomersEntity, bool> > queryExp1 = ct => ct.CustomerID < 50 && ct.CustomerCity == "B-City";
var translate = new SqlTranslateFormater();
string sql = translate.Translate(queryExp1);
Assert.Equal(sql, "CustomerID < 50 AND CustomerCity = 'B-City'");
}
/// <summary>
/// 解析型如“a=>a.id”的表达式，既 f(x':TModel) = x'.y':object
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="expr"></param>
/// <returns></returns>
internal static string TranslateObject <TModel>(Expression <Func <TModel, object> > expr, IDataProvider dp)
{
var exprVisitor = new SqlTranslateFormater();
exprVisitor.Provider = dp;
string cmd = exprVisitor.Translate(expr);
return(cmd);
}
/// <summary>
/// 解析整个表达式，转换为SQL语句
/// </summary>
/// <param name="expr"></param>
/// <returns></returns>
public static string TranslateConditional(Expression expr, IDataProvider dp)
{
var exprVisitor = new SqlTranslateFormater();
exprVisitor.Provider = dp;
string cmd = exprVisitor.Translate(expr);
return(cmd);
}
public void SimpleWhereTest2()
{
Expression <Func <CustomersEntity, bool> > queryExp1 = ct => ct.CustomerID == 1 &&
(ct.CustomerCity == "B-City" || ct.CustomerNumber == "0000");
var translate = new SqlTranslateFormater();
string sql = translate.Translate(queryExp1);
Assert.Equal(sql, "CustomerID = 1 AND (CustomerCity = 'B-City' OR CustomerNumber = '0000')");
}
public void SimpleWhereMethodTest3()
{
//IEnumerable<int> ids = new List<int>() { 40, 50 };//通过测试
//int[] ids = new[] {40, 50};//通过测试
List <int> ids = new List <int>()
{
40, 50
}; //通过测试
Expression <Func <CustomersEntity, bool> > queryExp1 = ct => ids.Contains(ct.CustomerID) && (SQLMethod.IsNull(ct.CustomerCity));
var translate = new SqlTranslateFormater();
string sql = translate.Translate(queryExp1);
Assert.Equal(sql, "CustomerID In (40,50) AND CustomerCity is NULL");
}
/// <summary>
/// 执行入口，解析表达式并生成执行SQL语句，返回SQL数据源数据
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public object Execute(Expression expression)
{
var t = new SqlTranslateFormater();
t.Provider = DataProvider;
string sql = t.Translate(expression);
DataProvider.Log = sql;
var reader = DataProvider.QueryData(new Command(sql));
Type elementType = TypeSystem.GetElementType(expression.Type);
return(Activator.CreateInstance(
typeof(ObjectReader <>).MakeGenericType(elementType),
BindingFlags.Instance | BindingFlags.NonPublic, null,
new object[] { reader },
null));
}
