Tech Tip: How to check the size of blobs via SQL
PRODUCT: 4D | VERSION: 12.3 | PLATFORM: Mac & Win
Published On: March 1, 2012
The BIT_LENGTH SQL function can easily be used in a SELECT statement to accomplish the task of getting the size of blobs. Here is an example:
ARRAY LONGINT($nSize_al) Begin SQL SELECT BIT_LENGTH(blob) FROM Table INTO :$nSize_al; End SQL |
In the example code above, the size of [Table]blob for all records is returned into the $nSize_al array.
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The BIT_LENGTH SQL function can also be used in a WHERE clause like this:
ARRAY LONGINT($nSize_al) Begin SQL SELECT ID FROM Table WHERE BIT_LENGTH(blob) > 1024 INTO :$nSize_al; End SQL |
In the example above, the $nSize_al array is filled with the [Table]ID for all records whose [Table]blob is greater than 1024 bits.
The BIT_LENGTH SQL function can be particularly useful when dealing with an external 4D database via SQL.