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Select last row in MySQL
How can I SELECT the last row in a MySQL table?
10 Answers
10
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Set selected option of select box
I want to set a option that was selected previously to be displayed on page load. I tried it with the following code:
16 An...
sql query to return differences between two tables
...colum C, here are the records, which are present in table A but not in B:
SELECT A.*
FROM A
LEFT JOIN B ON (A.C = B.C)
WHERE B.C IS NULL
To get all the differences with a single query, a full join must be used, like this:
SELECT A.*, B.*
FROM A
FULL JOIN B ON (A.C = B.C)
WHERE A.C IS NUL...
How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
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You are so close! All you need to do is select BOTH the home and its max date time, then join back to the topten table on BOTH fields:
SELECT tt.*
FROM topten tt
INNER JOIN
(SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home) groupedtt...
How to drive C#, C++ or Java compiler to compute 1+2+3+…+1000 at compile time?
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C# example to error at compile time.
class Foo
{
const char Sum = (1000 + 1) * 1000 / 2;
}
Produces the following compilation error:
Constant value '500500' cannot be converted to a 'char'
share
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boost多索引容器multi_index_container实战 - C/C++ - 清泛网 - 专注C/C++及内核技术
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typedef std::vector<Person::ptr> Persons;
int main(int argc, char *argv[]) {
if (argc != 2) {
printf("Usage: program count\n");
return 0;
}
PersonContainer container;
IdPersons idPersons;
NamePersons namePersons;
p...
1052: Column 'id' in field list is ambiguous
...and tbl_section which has both the id field in them. How do I go about selecting the id field, because I always get this error:
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Retrieving the last record in each group - MySQL
...x, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;
Below is the original answer I wrote for this question in 2009:
I write the solu...
Why do we need argc while there is always a null at the end of argv?
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...Which is a shame, in a way. If we had int main(char *argv[], int argc, ...), then some programs could just omit the argc because they do not need it. Opposite (needing argc but not argv) is probably never useful in a real program.
– hyde
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MySQL ON vs USING?
...n tables ON a column, a set of columns and even a condition. For example:
SELECT * FROM world.City JOIN world.Country ON (City.CountryCode = Country.Code) WHERE ...
USING is useful when both tables share a column of the exact same name on which they join. In this case, one may say:
SELECT ... FR...