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I am using postgreSQL. I have a column that:
NOT NULL
However when I want to insert a row with an empty string as like:
''
it doesn't give me an error and accepts. How can I check insert value should be not empty? (Neither empty nor null)
PS: My column defined as:
"ads" character varying(60) NOT NULL
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The IS NOT NULL condition is used in SQL to test for a non-NULL value. It returns TRUE if a non-NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.
Select non-empty column values using NOT IS NULL and TRIM() function. The syntax is as follows. SELECT * FROM yourTableName WHERE yourColumnName IS NOT NULL AND TRIM(yourColumnName) <> ' '; You can select non-empty value as well as whitespace from column using the same TRIM() function.
“sql not null or empty” Code Answer'sThe NOT NULL constraint enforces a column to NOT accept NULL values. This enforces a field to always contain a value, which means that you cannot insert a new record, or update a record without adding a value to this field.
If != and <> both are the same, which one should be used in SQL queries? Here is the answer – You can use either != or <> both in your queries as both technically same but I prefer to use <> as that is SQL-92 standard.
Add a constraint to column definition. For example something like:
ads character varying(60) NOT NULL CHECK (ads <> '')
For more, see http://www.postgresql.org/docs/current/static/ddl-constraints.html
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