The CONCAT_WS function returns NULL if and only if the first argument, which is the separator, is NULL.
#Mysql concat fails on null code#
The following statement concatenates two string values: John and Doe, and separates these two strings by a comma: SELECT CONCAT_WS( ',', 'John', 'Doe') Code language: SQL (Structured Query Language) ( sql ) The CONCAT_WS function adds the separator between string arguments and returns a single string with the separator inserted between string arguments. The first argument is the separator for other arguments: string1, string2, … ) Code language: SQL (Structured Query Language) ( sql ) The following illustrates the syntax of the CONCAT_WS function: CONCAT_WS(seperator,string1,string2. The CONCAT_WS function concatenates two or more string values with a predefined separator. MySQL provides a special form of the CONCAT function: CONCAT_WS function. Try It Out MySQL CONCAT_WS function: Concatenate strings with a separator
#Mysql concat fails on null full#
To get the full names of contacts, you use the CONCAT function to concatenate first name, space, last name as the following statement: SELECT concat(contactFirstName, ' ',contactLastName) FullnameĬustomers Code language: SQL (Structured Query Language) ( sql ) See the following customers table in the sample database. If you add a NULL value, the CONCAT function returns a NULL value as follows: SELECT CONCAT( 'MySQL', NULL, 'CONCAT') Code language: SQL (Structured Query Language) ( sql ) SELECT CONCAT( 'MySQL', 'CONCAT') Code language: SQL (Structured Query Language) ( sql ) The following statement concatenates two quoted strings: MySQL and CONCAT. If any argument is NULL, the CONCAT function returns a NULL value. The CONCAT function converts all arguments to the string type before concatenating.
The following illustrates the syntax of the CONCAT function. The CONCAT function requires a minimum of one parameter otherwise it raises an error. The MySQL CONCAT function takes one or more string arguments and concatenates them into a single string. In Microsoft SQL server, you use the addition arithmetic operator (+) to concatenate string values.īesides using spaces for string concatenation, MySQL provides two other functions that concatenate string values: CONCAT and CONCAT_WS. For example, if you use PostgreSQL or Oracle, you have to use the string concatenation operator ||. MySQL string concatenation is cleaner in comparison with other database management systems.
To concatenate two or more quoted string values, you place the string next to each other as the following syntax: SELECT 'MySQL ' 'String ' 'Concatenation' Code language: SQL (Structured Query Language) ( sql ) Summary: in this tutorial, you will learn various ways to concatenate two or more strings together by using the MySQL CONCAT and CONCAT_WS functions.
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