{"id":5231,"date":"2013-04-09T00:00:17","date_gmt":"2013-04-09T00:00:17","guid":{"rendered":"http:\/\/craftydba.com\/?p=5231"},"modified":"2017-10-11T16:20:16","modified_gmt":"2017-10-11T16:20:16","slug":"string-functions-left","status":"publish","type":"post","link":"https:\/\/craftydba.com\/?p=5231","title":{"rendered":"String Functions &#8211; LEFT()"},"content":{"rendered":"<p><a href=\"https:\/\/craftydba.com\/wp-content\/uploads\/2013\/04\/turquoise-yarn-md.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-thumbnail wp-image-5158\" title=\"turquoise-yarn-md\" src=\"https:\/\/craftydba.com\/wp-content\/uploads\/2013\/04\/turquoise-yarn-md-150x150.png\" alt=\"\" width=\"150\" height=\"150\" \/><\/a><br \/>\nI am going to continue my series of very short articles or tidbits on Transaction SQL string functions. I will exploring the LEFT() function today.<\/p>\n<p>The <a href=\"http:\/\/msdn.microsoft.com\/en-us\/library\/ms177601.aspx\">LEFT()<\/a> function takes the source string [S] and number of characters [X] as input and returns the [X] leftmost characters from string [S] as output.<\/p>\n<p>The following example grabs the first word from a favorite movie title of mine.<\/p>\n<pre class=\"lang:TSQL theme:familiar mark:1,2-3\" title=\"string functions - left()\">\r\n-- Return first word\r\nselect left('wizard of oz', 6) as str_word\r\n<\/pre>\n<\/p>\n<pre class=\"lang:TSQL theme:epicgeeks\" title=\"output\">\r\noutput: \r\n\r\nstr_word\r\n-----------\r\nwizard\r\n<\/pre>\n<\/p>\n<p>One thing to always worry about when using TSQL functions is how will it react with empty strings, NULL values, or invalid values?  Both empty strings and NULL values as inputs return themselves as outputs.  A negative number for input [X] will result in a error being throw.<\/p>\n<pre class=\"lang:TSQL theme:familiar mark:1,2-3\" title=\"string functions - left()\">\r\n-- Invalid length\r\nselect left('wizard of oz', -1) as str_word\r\n\r\n-- Empty string returns empty string\r\nselect left('', 6) as str_word\r\n\r\n-- Null returns Null\r\nselect left(NULL, 6) as str_word\r\n<\/pre>\n<\/p>\n<pre class=\"lang:TSQL theme:epicgeeks\" title=\"output\">\r\noutput: \r\n\r\nMsg 536, Level 16, State 1, Line 2\r\nInvalid length parameter passed to the left function.\r\n\r\nstr_word\r\n--------\r\n\r\nstr_word\r\n--------\r\nNULL\r\n<\/pre>\n<\/p>\n<p>Next time, I will be exploring the <a href=\"http:\/\/msdn.microsoft.com\/en-us\/library\/ms190329.aspx\">LEN()<\/a> function.  <\/p>\n","protected":false},"excerpt":{"rendered":"<p>I am going to continue my series of very short articles or tidbits on Transaction SQL string functions. I will exploring the LEFT() function today. The LEFT() function takes the source string [S] and number of characters [X] as input and returns the [X] leftmost characters from string [S] as output. The following example grabs the first word from a favorite movie title of mine. &#8212; Return first word select left(&#8216;wizard of oz&#8217;, 6) as str_word output: str_word &#8212;&#8212;&#8212;&#8211; wizard One thing to always worry about when using TSQL functions&hellip;<\/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":[31,15,820,815,29],"class_list":["post-5231","post","type-post","status-publish","format-standard","hentry","category-very-short-articles","tag-database-developer","tag-john-f-miner-iii","tag-left","tag-string-function","tag-tsql"],"_links":{"self":[{"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/posts\/5231","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=5231"}],"version-history":[{"count":0,"href":"https:\/\/craftydba.com\/index.php?rest_route=\/wp\/v2\/posts\/5231\/revisions"}],"wp:attachment":[{"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5231"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5231"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/craftydba.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5231"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}