大约有 3,551 项符合查询结果（耗时：0.0194秒） [XML]
What is the reason for having '//' in Python? [duplicate]
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Python's 2 approach to "/" is not really bad. In SQL, we have to deal with it as well. Its common to see (0.0+variable1)/variable2 or 1.0*variable1/variable2
– Chris
Oct 28 '15 at 13:42
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Distinct in Linq based on only one field of the table
...able out, you will only get those items. If you are talking about LINQ to SQL, then yes, this will do a table scan.
– PRMan
May 11 '17 at 16:00
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SELECT INTO Variable in MySQL DECLARE causes syntax error?
... same issue, but I think I know what's causing the confusion. If you use MySql Query Analyzer, you can do this just fine:
SELECT myvalue
INTO @myvar
FROM mytable
WHERE anothervalue = 1;
However, if you put that same query in MySql Workbench, it will throw a syntax error. I don't know why they ...
Drop all duplicate rows across multiple columns in Python Pandas
...examples will remove all duplicates and keep one, similar to DISTINCT * in SQL
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PHP PDO returning single row
...ing a variable for the SELECT function with a PDO query. I will delete the sql injection comment from my answer just to make your day (and mine).
– user3162468
Jun 12 '14 at 5:51
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In MySQL, how to copy the content of one table to another table within the same database?
I am new to MySQL. I would like to copy the content of one table to another table within the same database. Basically, I would like to insert to a table from another table. Is there easy way of doing this?
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Number of occurrences of a character in a string [duplicate]
...ick, however that is better suited for languages where looping is awkward (SQL) or slow (VBScript):
int cnt = test.Length - test.Replace("&", "").Length;
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How to use GROUP BY to concatenate strings in MySQL?
...d, GROUP_CONCAT(name SEPARATOR ' ') FROM table GROUP BY id;
http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
From the link above, GROUP_CONCAT: This function returns a string result with the concatenated non-NULL values from a group. It returns NULL if there ar...
mongo group query how to keep fields
...e key(s) in arguments. How to keep the first document in each group like mysql query group.
for example:
11 Answers
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PHP date() format when inserting into datetime in MySQL
...ss to the date() function in PHP if I want to insert the result into a MySQL datetime type column?
13 Answers
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