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Truncate all tables in a MySQL database in one command?
...
truncate multiple database tables on Mysql instance
SELECT Concat('TRUNCATE TABLE ',table_schema,'.',TABLE_NAME, ';')
FROM INFORMATION_SCHEMA.TABLES where table_schema in ('db1_name','db2_name');
Use Query Result to truncate tables
Note:
may be you will get this error:
...
Alter MySQL table to add comments on columns
...
Script for all fields on database:
SELECT
table_name,
column_name,
CONCAT('ALTER TABLE `',
TABLE_SCHEMA,
'`.`',
table_name,
'` CHANGE `',
column_name,
'` `',
column_name,
'` ',
column_type,
' ',
IF(is_nul...
Javascript reduce on array of objects
...dyFound = (words, word) => words.includes(word)
? words
: words.concat(word);
const deduplicatedWords = aBunchOfWords.reduce(skipIfAlreadyFound, []);
Providing a count of all words found:
const incrementWordCount = (counts, word) => {
counts[word] = (counts[word] || 0) + 1;
ret...
Why is string concatenation faster than array join?
Today, I read this thread about the speed of string concatenation.
9 Answers
9
...
How to scroll up or down the page to an anchor using jQuery?
...script does not have string interpolation, so using + with strings or vars concatenates them, like: "#some_anchor". Really, the second concat anchor_id + "" is not needed, I believe.
– onebree
Sep 26 '16 at 20:25
...
How to convert number to words in java
...ERO_TOKEN;
} else if (negative) {
name = MINUS.concat(SEPARATOR).concat(name);
}
if (!(null == decimalValue || decimalValue.isEmpty())) {
name = name.concat(SEPARATOR).concat(UNION_AND).concat(SEPARATOR)
.conca...
add column to mysql table if it does not exist
...me_IN, field_name_IN);
IF (@isFieldThere = 0) THEN
SET @ddl = CONCAT('ALTER TABLE ', table_name_IN);
SET @ddl = CONCAT(@ddl, ' ', 'ADD COLUMN') ;
SET @ddl = CONCAT(@ddl, ' ', field_name_IN);
SET @ddl = CONCAT(@ddl, ' ', field_definition_IN);
PREPARE stmt...
How to get the first and last date of the current year?
...
To get the first and the last day of the year, one can use the CONCAT function. The resulting value may be cast to any type.
CONCAT(YEAR(Getdate()),'-01-01') FirstOfYear,
CONCAT(YEAR(GETDATE()),'-12-31') LastOfYear
...
MySQL stored procedure vs function, which would I use when?
...TE FUNCTION hello (s CHAR(20))
RETURNS CHAR(50) DETERMINISTIC
RETURN CONCAT('Hello, ',s,'!');
Query OK, 0 rows affected (0.00 sec)
CREATE TABLE names (id int, name varchar(20));
INSERT INTO names VALUES (1, 'Bob');
INSERT INTO names VALUES (2, 'John');
INSERT INTO names VALUES (3, 'Paul');
S...
Hidden Features of MySQL
...ntryCode,Language)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
Feature: GROUP_CONCAT() aggregate function
Creates a concatenated string of its arguments per detail, and aggregates by concatenating those per group.
Example 1: simple
SELECT CountryCode
, GROUP_CONCAT(Language) AS List
FROM ...