Search results
17 mar 2011 · Just use the insert query and put the NULL keyword without quotes. That will work-INSERT INTO `myDatabase`.`myTable` (`myColumn`) VALUES (NULL);
5.3.4.6 Working with NULL Values. The NULL value can be surprising until you get used to it. Conceptually, NULL means “a missing unknown value” and it is treated somewhat differently from other values. To test for NULL, use the IS NULL and IS. NOT NULL operators, as shown here:
What is a NULL Value? A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field. Then, the field will be saved with a NULL value.
You can use a NULL value in the INSERT statement to specify that the data is missing. For example, the following statement inserts a row into the leads table. Because the phone number is missing, so a NULL value is used. INSERT INTO leads(first_name,last_name, source,email,phone)
31 lip 2024 · We can insert NULL values into the columns that allow them: INSERT INTO employees (name, salary) VALUES ('Alice', NULL); INSERT INTO employees (name, salary) VALUES (NULL, 50000.00); Querying NULL Values. To handle NULL values in queries we must use specific SQL functions and operators.
17 lip 2024 · Domyślnie, MySQL wstawi wartości NULL w kolumnach pominiętych w zapytaniu INSERT. Wstawmy teraz akt Leslie, który zawiera datę urodzenia. Wartość daty należy ująć w pojedynczy cudzysłów w formacie „RRRR-MM-DD”.
You can add an index on a column that can have NULL values if you are using the MyISAM, InnoDB, or MEMORY storage engine. Otherwise, you must declare an indexed column NOT NULL, and you cannot insert NULL into the column.
