{"id":5270,"date":"2013-04-14T00:00:38","date_gmt":"2013-04-14T00:00:38","guid":{"rendered":"http:\/\/craftydba.com\/?p=5270"},"modified":"2017-10-11T16:11:56","modified_gmt":"2017-10-11T16:11:56","slug":"string-functions-patindex","status":"publish","type":"post","link":"https:\/\/craftydba.com\/?p=5270","title":{"rendered":"String Functions – PATINDEX()"},"content":{"rendered":"

\"\"<\/a>
\nI am going to continue my series of very short articles or tidbits on Transaction SQL string functions. I will exploring the PATINDEX() function today.<\/p>\n

The PATINDEX()<\/a> function takes a search pattern to find and a expression to search as input parameters. It returns the first position in which the search pattern was found. Unlike the CHARINDEX()<\/a> function, wild card characters<\/a> such as %, _, and ^ can be used used to define the pattern. In a nutshell, it is a fuzzy match that is performed.<\/p>\n

The following example is based upon the television jingle<\/a> that I heard as a kid for Trix<\/a> cereal.<\/p>\n

The example below contains four test cases:<\/p>\n

    \n
  1. Word is found in target string.<\/span><\/li>\n
  2. Word is not found in target string.<\/span><\/li>\n
  3. Starting position any word that starts with tr<\/b>.<\/span><\/li>\n
  4. NULL expression to find.<\/span><\/li>\n
  5. NULL expression to search.<\/span><\/li>\n<\/ol>\n
    \r\n\r\n-- Set local variables\r\ndeclare @var_jingle varchar(512)\r\n    = 'silly rabbit trix are for kids';\r\ndeclare @var_find varchar(16)\r\n    = '%rabbit%';\r\n\r\n-- Find location of rabbit (7)\r\nselect patindex(@var_find, @var_jingle) as pos1;\r\n\r\n-- Find location of rabies (0)\r\nselect patindex('%rabies%', @var_jingle) as pos2;\r\n\r\n-- Find location of any word starting with tr, 14\r\nselect patindex('%tr__%', @var_jingle) as pos3;\r\n\r\n-- Null search string, NULL\r\nselect patindex(NULL, @var_jingle) as pos4;\r\n\r\n-- Null source string, error\r\nselect patindex(@var_find, NULL) as pos5;\r\n\r\n<\/pre>\n<\/p>\n
    The results of four test cases are the following:<\/p>\n
      \n
    1. 7 – Seventh character position is start of string.<\/span><\/li>\n
    2. 0 – Expression to find not found.<\/span><\/li>\n
    3. 14 – Expression is matched to trix.<\/span><\/li>\n
    4. NULL – Position is unknown.<\/span><\/li>\n
    5. ERROR – This function call generates an error.<\/span><\/li>\n<\/ol>\n
      \r\noutput: \r\n\r\npos1\r\n-----------\r\n7\r\n\r\npos2\r\n-----------\r\n0\r\n\r\npos3\r\n-----------\r\n14\r\n\r\npos4\r\n-----------\r\nNULL\r\n\r\nMsg 8116, Level 16, State 1, Line 20\r\nArgument data type NULL is invalid for argument 2 of patindex function.\r\n<\/pre>\n<\/p>\n
      Next time, I will be exploring the QUOTENAME()<\/a> function that comes in handy when creating dynamic TSQL with object names that might need to be quoted.<\/p>\n","protected":false},"excerpt":{"rendered":"
      I am going to continue my series of very short articles or tidbits on Transaction SQL string functions. I will exploring the PATINDEX() function today. The PATINDEX() function takes a search pattern to find and a expression to search as input parameters. It returns the first position in which the search pattern was found. Unlike the CHARINDEX() function, wild card characters such as %, _, and ^ can be used used to define the pattern. In a nutshell, it is a fuzzy match that is performed. The following example is…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[814],"tags":[31,15,823,815,29],"class_list":["post-5270","post","type-post","status-publish","format-standard","hentry","category-very-short-articles","tag-database-developer","tag-john-f-miner-iii","tag-patindex","tag-string-function","tag-tsql"],"_links":{"self":[{"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/posts\/5270","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5270"}],"version-history":[{"count":0,"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/posts\/5270\/revisions"}],"wp:attachment":[{"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5270"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5270"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5270"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}