mysql - How often does a character occur in the first position vs the second position of a string? -
i trying answer question:
how character occur in first position versus second position of string?
using sql query on mysql.
however syntax error.
the code:
select onechar, ascii(onechar) asciival, count(*) cnt, sum(case when pos = 1 1 else 0 end) pos_1, sum(case when pos = 2 1 else 0 end) pos_2 ( (select substring(`city`, 1, 1) onechar, 1 pos `orders` len(`city` >= 1 ) union (select substring(`city`, 2, 1) onechar, 2 pos `orders` len(`city` >= 2) ) group onechar order onechar
the error:
you have error in sql syntax; check manual corresponds mysql server version right syntax use near 'group onechar order onechar limit 0, 30' @ line 1
tried several ways without success.
anyone give me light on problem?
the parenthesis incorrect , query missing alias derived table. also, because mysql evaluates booleans 1 or 0 can simplify sum
statements. try this:
select onechar, ascii(onechar) asciival, count(*) cnt, sum(pos = 1) pos_1, sum(pos = 2) pos_2 ( select substring(`city`, 1, 1) onechar, 1 pos `orders` length(`city`) >= 1 union select substring(`city`, 2, 1) onechar, 2 pos `orders` length(`city`) >= 2 ) t group onechar order onechar
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