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Repair all tables in one go
...ry to print REPAIR SQL statments for all tables inside a database:
select concat('REPAIR TABLE ', table_name, ';') from information_schema.tables
where table_schema='mydatabase';
After that copy all the queries and execute it on mydatabase.
Note: replace mydatabase with desired DB name
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How to get all columns' names for all the tables in MySQL?
...omma-delimited list of the columns in each table:
SELECT table_name,GROUP_CONCAT(column_name ORDER BY ordinal_position)
FROM information_schema.columns
WHERE table_schema = DATABASE()
GROUP BY table_name
ORDER BY table_name
Note : When using tables with a high number of columns and/or with long f...
MySQL search and replace some text in a field
...t to search and replace based on the value of another field you could do a CONCAT:
update table_name set `field_name` = replace(`field_name`,'YOUR_OLD_STRING',CONCAT('NEW_STRING',`OTHER_FIELD_VALUE`,'AFTER_IF_NEEDED'));
Just to have this one here so that others will find it at once.
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How to convert an int array to String with toString method in Java [duplicate]
...
.mapToObj(String::valueOf)
.reduce((a, b) -> a.concat(",").concat(b))
.get();
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How to see indexes for a database or table in MySQL?
...ed database.
SELECT TABLE_NAME,
COUNT(1) index_count,
GROUP_CONCAT(DISTINCT(index_name) SEPARATOR ',\n ') indexes
FROM INFORMATION_SCHEMA.STATISTICS
WHERE TABLE_SCHEMA = 'mydb'
AND INDEX_NAME != 'primary'
GROUP BY TABLE_NAME
ORDER BY COUNT(1) DESC;
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selecting unique values from a column
...you also want to output products details per date as JSON.
SELECT `date`,
CONCAT('{',GROUP_CONCAT('{\"id\": \"',`product_id`,'\",\"name\": \"',`product_name`,'\"}'),'}') as `productsJSON`
FROM `buy` group by `date`
order by `date` DESC
product_id product_name date
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How to use a servlet filter in Java to change an incoming servlet request url?
...h.
Use straightforward java.lang.String methods like substring(), split(), concat() and so on to extract the part of interest and compose the new path.
Use either ServletRequest#getRequestDispatcher() and then RequestDispatcher#forward() to forward the request/response to the new URL (server-side re...
Array_merge versus + [duplicate]
... instead using two new functions we wrote. "array_merge_by_key" and "array_concat" instead of a single function with a heuristic that tries to guess at what you want
– Yuliy
Jul 28 '14 at 0:38
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Prepend text to beginning of string
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Since we want to test prepend, and not just concatenate, I've updated the tests: jsperf.com/prepend-text-to-string/5
– metalim
Apr 22 '19 at 11:32
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const char* concatenation
I need to concatenate two const chars like these:
12 Answers
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