大约有 37,000 项符合查询结果（耗时：0.0250秒） [XML]
How to test an SQL Update statement before running it?
...man/5.0/en/commit.html
For example:
START TRANSACTION;
SELECT * FROM nicetable WHERE somthing=1;
UPDATE nicetable SET nicefield='VALUE' WHERE somthing=1;
SELECT * FROM nicetable WHERE somthing=1; #check
COMMIT;
# or if you want to reset changes
ROLLBACK;
SELECT * FROM nicetable WHERE somthing=1...
Can I use a function for a default value in MySql?
...ntheses to distinguish them from literal constant default values.
CREATE TABLE t1 (
uuid_field VARCHAR(32) DEFAULT (uuid()),
binary_uuid BINARY(16) DEFAULT (UUID_TO_BIN(UUID()))
);
share
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Keeping it simple and how to do multiple CTE in a query
I have this simple T-SQL query, it emits a bunch of columns from a table and also joins information from other related tables.
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Can I change a column from NOT NULL to NULL without dropping it?
Need to alter a table to allow nulls on a column -- but cant drop the column...can I do this? Was trying something like:
3...
MySQL case sensitive query [duplicate]
.... However it will return 'VALUE', 'value', 'VaLuE', etc…
SELECT * FROM `table` WHERE `column` = 'value'
The good news is that if you need to make a case-sensitive query, it is very easy to do using the BINARY operator, which forces a byte by byte comparison:
SELECT * FROM `table` WHERE BINARY ...
SQL Server : GROUP BY clause to get comma-separated values [duplicate]
...ECT ReportId, Email =
STUFF((SELECT ', ' + Email
FROM your_table b
WHERE b.ReportId = a.ReportId
FOR XML PATH('')), 1, 2, '')
FROM your_table a
GROUP BY ReportId
SQL fiddle demo
sha...
正确重置MySQL密码 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...下面是错误答案：
首先停止MySQL服务，然后使用skip-grant-tables参数启动它：
shell> /etc/init.d/mysql stopshell> mysqld_safe --skip-grant-tables &
此时无需授权就可以进入到MySQL命令行，使用SQL重置MySQL密码：
UPDATE mysql.user SET Password=PASSWORD('......
正确重置MySQL密码 - 爬虫/数据库 - 清泛IT社区，为创新赋能！
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下面是错误答案：首先停止MySQL服务，然后使用skip-grant-tables参数启动它：shell> /etc/init.d/mysql stopshell> mysqld_safe --skip-grant-tables &此时无需授权就可以进入到MySQL命令行，使用SQL重置MySQL密码：UPDATE mysql.user SET Password=PASSWORD(...
How to select the rows with maximum values in each group with dplyr? [duplicate]
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For me, it helped to count the number of values per group. Copy the count table into a new object. Then filter for the max of the group based on the first grouping characteristic. For example:
count_table <- df %>%
group_by(A, B) %>%
count() %>%
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How do we count rows using older versions of Hibernate (~2009)?
For example, if we have a table Books, how would we count total number of book records with hibernate?
8 Answers
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