Issues

LinqSharp.EFCore

.NET Function	Jet	MySql	Oracle	PostgreSQL	Sqlite	SqlServer
DbFunc.Random	✔️	✔️	✔️	✔️	✔️	✔️
DbFunc.Concat	❌	✔️	✔️	✔️	❌	✔️
DbFunc.DateTime	❌	✔️	❌	❌	❌	✔️

For example, EntityFramework can not translate this expression:

.Where(x => new DateTime(x.Year, x.Month, x.Day) > DateTime.Now);

So, we provide another function to support this:

.Where(x => DbFunc.DateTime(x.Year, x.Month, x.Day) > DateTime.Now);

If use MySQL, the generated SQL is:

WHERE STR_TO_DATE(CONCAT(`x`.`Year`, '-', `x`.`Month`, '-', `x`.`Day`), '%Y-%m-%d') = CURRENT_TIMESTAMP();

In SQLServer

Use:

.Where(x => DbFunc.DateTime(x.Year, x.Month, x.Day) > DbFunc.DateTime(2012, 4, 16));

CONVERT(DATETIME, CONCAT([x].[Year], N'-', [x].[Month], N'-', [x].[Day])) > CONVERT(DATETIME, CONCAT(2012, N'-', 4, N'-', 16))

!! Not Use:

// Wrong
.Where(x => DbFunc.DateTime(x.Year, x.Month, x.Day) > new DateTime(2012, 4, 16));

/* Wrong */
WHERE CONVERT(DATETIME, CONCAT([x].[Year], N'-', [x].[Month], N'-', [x].[Day])) > TIMESTAMP '2012-04-16T00:00:00.0000000'

In MySql

Everything is OK.

.Where(x => DbFunc.DateTime(x.Year, x.Month, x.Day) > DbFunc.DateTime(2012, 4, 16));

WHERE STR_TO_DATE(CONCAT(`x`.`Year`, '-', `x`.`Month`, '-', `x`.`Day`), '%Y-%m-%d')
> STR_TO_DATE(CONCAT(2012, '-', 4, '-', 16), '%Y-%m-%d');

.Where(x => DbFunc.DateTime(x.Year, x.Month, x.Day) > new DateTime(2012, 4, 16));

WHERE STR_TO_DATE(CONCAT(`x`.`Year`, '-', `x`.`Month`, '-', `x`.`Day`), '%Y-%m-%d')
> '2012-04-16 00:00:00.000000';