How to skip null values in string concatenation in sql
When concatenating strings in SQL, you can skip null values through the following methods: COALESCE() function: Returns the first non-NULL value. IFNULL() function: If the first parameter is not NULL, returns the first parameter, otherwise returns the second parameter. ISNULL() function: Checks whether a value is NULL and returns TRUE or FALSE accordingly.
SQL string splicing skips null values
When splicing strings in SQL, if a null value is encountered value, usually returns NULL, thus affecting the splicing result. To skip null values, you can use the following method:
COALESCE() function:
COALESCE() The function returns the first non-NULL The value of Returns a complete name string containing first and last name.
IFNULL() If the first parameter is not NULL, the function returns the first parameter, otherwise Return the second parameter, the syntax is as follows:
COALESCE(value1, value2, ...)
For example: SELECT COALESCE(name, '') || ' ' || COALESCE(surname, '') AS full_name
FROM table_name;
This query has the same effect as using the
function.
ISNULL() Function checks whether a value is NULL. If it is NULL, it returns TRUE, otherwise it returns FALSE, the syntax is as follows:
IFNULL(value1, value2)
For example: statement. If are returned. The above is the detailed content of How to skip null values in string concatenation in sql. For more information, please follow other related articles on the PHP Chinese website!SELECT IFNULL(name, '') || ' ' || IFNULL(surname, '') AS full_name
FROM table_name;
This query uses the CASEsurname is NULL, an empty string is returned. Otherwise, spaces and Note: When using these methods, ensure that the replacement value is compatible with the string type to be concatenated.
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