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Adding multiple columns AFTER a specific column in MySQL
...ermitted in a single ALTER TABLE statement, separated by commas. This is a MySQL extension to standard SQL, which permits only one of each clause per ALTER TABLE statement.
– informatik01
May 1 '19 at 13:21
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When to use MyISAM and InnoDB? [duplicate]
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Read about Storage Engines.
MyISAM:
The MyISAM storage engine in MySQL.
Simpler to design and create, thus better for beginners. No worries about the foreign relationships between tables.
Faster than InnoDB on the whole as a result of the simpler structure thus much less costs of server ...
Alter MySQL table to add comments on columns
I have been checking the MySQL Documentation for ALTER TABLE and it does not seem to include a way to add or modify a comment to a column. How can I do this?
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ROW_NUMBER() in MySQL
Is there a nice way in MySQL to replicate the SQL Server function ROW_NUMBER() ?
24 Answers
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How to update column with null value
I am using mysql and need to update a column with a null value. I have tried this many different ways and the best I have gotten is an empty string.
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Set NOW() as Default Value for datetime datatype?
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As of MySQL 5.6.5, you can use the DATETIME type with a dynamic default value:
CREATE TABLE foo (
creation_time DATETIME DEFAULT CURRENT_TIMESTAMP,
modification_time DATETIME ON UPDATE CURRENT_TIMESTAMP
)
Or even...
MySQL - Make an existing Field Unique
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ALTER IGNORE TABLE mytbl ADD UNIQUE (columnName);
For MySQL 5.7.4 or later:
ALTER TABLE mytbl ADD UNIQUE (columnName);
As of MySQL 5.7.4, the IGNORE clause for ALTER TABLE is removed and
its use produces an error.
So, make sure to remove duplicate entries first as IGNO...
How to disable and re-enable console logging in Python?
...an answer as blocking propagation effectively disables all handlers of the root logger and the question clearly states (…) but I may have other handlers there that I want to keep which suggests the intention is to disable default StreamHandler of the root logger only.
– Piotr...
转型产品经理必看 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...文章。创办人人都是产品经理以来，每天都有很多人问我如何转型做产品经理、转型产品经理会遇到哪些问题，其实我一直没能回答好这个问题，因为我从运营转型产品经理的过程太顺利，并且转型的过程也没有做太多的思考和...
Creating a simple XML file using python
...nt using the in-stdlib cElementTree:
import xml.etree.cElementTree as ET
root = ET.Element("root")
doc = ET.SubElement(root, "doc")
ET.SubElement(doc, "field1", name="blah").text = "some value1"
ET.SubElement(doc, "field2", name="asdfasd").text = "some vlaue2"
tree = ET.ElementTree(root)
tree.wr...