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# ISDATE

`ISDATE` fonksiyonu, verilen değerin bir tarih veri tipi değeri olup olmadığını kontrol eder. Fonksiyon şu şekilde kullanılır:

```sql
ISDATE(expression)
```

* `expression`: kontrol edilmek istenen değer

Örnek olarak:

```sql
DECLARE @string_value VARCHAR(50) = '2022-01-01';
IF ISDATE(@string_value) = 1
    PRINT 'The value is a valid date';
ELSE
    PRINT 'The value is not a valid date';
```

Bu örnekte, `@string_value` değişkenindeki değerin `'2022-01-01'` tarih veri tipi değeri olup olmadığı kontrol edilir ve eğer bu değer tarih veri tipi ise, ekrana `"The value is a valid date"` yazdırılır.


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