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concat function

The concat() and concat_ws() functions return strings concatenated by one or more strings.

concat() function

The concat() function requires at least two or more strings. All the parameters are concatenated into one string.

  • If there is only one string, the string itself is returned.
  • If any one of the strings is NULL, NULL is returned.

Syntax

bash concat(string1,string2,...)

Examples

```bash //This example concatenates 1, 2, and 3. nebula> RETURN concat("1","2","3") AS r; +-------+ | r | +-------+ | "123" | +-------+

//In this example, one of the string is NULL. nebula> RETURN concat("1","2",NULL) AS r; +----------+ | r | +----------+ | NULL | +----------+

nebula> GO FROM "player100" over follow \ YIELD concat(src(edge), properties(\(^).age, properties(\)$).name, properties(edge).degree) AS A; +------------------------------+ | A | +------------------------------+ | "player10042Tony Parker95" | | "player10042Manu Ginobili95" | +------------------------------+ ```

concat_ws() function

The concat_ws() function connects two or more strings with a predefined separator.

  • If the separator is NULL, the concat_ws() function returns NULL.
  • If the separator is not NULL and there is only one string, the string itself is returned.
  • If the separator is not NULL and there is a NULL in the strings, NULL is ignored during the concatenation.

Syntax

bash concat_ws(separator,string1,string2,... )

Examples

```bash //This example concatenates a, b, and c with the separator +. nebula> RETURN concat_ws("+","a","b","c") AS r; +---------+ | r | +---------+ | "a+b+c" | +---------+

//In this example, the separator is NULL. neubla> RETURN concat_ws(NULL,"a","b","c") AS r; +----------+ | r | +----------+ | NULL | +----------+

//In this example, the separator is + and there is a NULL in the strings. nebula> RETURN concat_ws("+","a",NULL,"b","c") AS r; +---------+ | r | +---------+ | "a+b+c" | +---------+

//In this example, the separator is + and there is only one string. nebula> RETURN concat_ws("+","a") AS r; +-----+ | r | +-----+ | "a" | +-----+

nebula> GO FROM "player100" over follow \ YIELD concat_ws(" ",src(edge), properties(\(^).age, properties(\)$).name, properties(edge).degree) AS A; +---------------------------------+ | A | +---------------------------------+ | "player100 42 Tony Parker 95" | | "player100 42 Manu Ginobili 95" | +---------------------------------+ ```

Last update: October 27, 2021