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summer12in
Starting Member
6 Posts |
 Posted - 2015-01-09 : 01:46:43
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| am very new in sql programming .i have 2 questions based on the below mentioned queryWITH CTE_Stars AS( SELECT CONVERT(VARCHAR(10), '*') Stars UNION ALL SELECT CONVERT(VARCHAR(10), CTE_Stars.Stars+'*') Stars FROM CTE_Stars WHERE LEN(Stars) < 6)SELECT * FROM CTE_StarsCan someone explain how the above query is working and second this query does not work without convert function why..? Why do we need to convert '*' to character? By default * datatype is character only.This query is giving output in 5 rows and that to without a loop.. how is this possibleSamarjeet |
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gbritton
Master Smack Fu Yak Hacker
2780 Posts |
Posted - 2015-01-09 : 07:00:07
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| under the covers I select is a loop. Sql generates code that itterates over the dataset. In your case your cte is what is called a recursive CTE. And those recursive calls essentially form the loop. The reason the cast to varchar 10 is to hold a strain greater than one character. If I read it right. BTW, that's a terrible way to get that job done! |
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summer12in
Starting Member
6 Posts |
Posted - 2015-01-09 : 13:13:09
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| Great explanation..i got it now ...Samarjeet |
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can somone explain the CTE code below