[FLINK-6925] Add CONCAT/CONCAT_WS supported in SQL

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.0
• Fix Version/s: 1.4.0
• Component/s: Table SQL / API
• Assignee: sunjincheng
• Reporter: sunjincheng
• Created: 15/Jun/17 07:46
• Updated: 05/Jul/17 15:24
• Resolved: 05/Jul/17 15:24

Description

CONCAT(str1,str2,...)Returns the string that results from concatenating the arguments. May have one or more arguments. If all arguments are nonbinary strings, the result is a nonbinary string. If the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent nonbinary string form.

CONCAT() returns NULL if any argument is NULL.

• Syntax:
  CONCAT(str1,str2,...)

• Arguments
  • str1,str2,... -

• Return Types
  string

• Example:
  CONCAT('F', 'lin', 'k') -> 'Flink'
  CONCAT('M', NULL, 'L') -> NULL
  CONCAT(14.3) -> '14.3'

• See more:
  • MySQL

CONCAT_WS() stands for Concatenate With Separator and is a special form of CONCAT(). The first argument is the separator for the rest of the arguments. The separator is added between the strings to be concatenated. The separator can be a string, as can the rest of the arguments. If the separator is NULL, the result is NULL.

• Syntax:
  CONCAT_WS(separator,str1,str2,...)

• Arguments
  • separator -
  • str1,str2,... -

• Return Types
  string

• Example:
  CONCAT_WS(',','First name','Second name','Last Name') -> 'First name,Second name,Last Name'

• See more:
  • MySQL

Issue Links

• blocks: FLINK-6975 Add CONCAT/CONCAT_WS supported in TableAPI
• links to: GitHub Pull Request #4138