How to prevent inserting empty string in SQL Server?

Setting a field not null doesn’t mean this field doesn’t accept blank strings too! so for preventing empty strings, beside not null definition just add a check constrain to check the empty ones.

create table t(n varchar(64) not null ,constraint chkn check (ltrim(n)!=”));
insert t values('Danial (this is okay!)'),
		('   Pedram (this is okay too!)'),
		('        Code Project folks(this is still okay!)!      '),
		('    '/*Not okay!*/),(null /*Not okay!*/ );

simple remove the spaces with ltrim() function, and check the value should not be as a empty string ”.

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