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[MySQL learning 09]

2022-07-25 11:41:00 【88 year old programming with injury】

mysql Study

The increase of data 、 Delete 、 Change

insert data

Mode one ： Insert data one by one
The added field is not specified , Fields must be added in the order of table structure declaration
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You can also specify the added fields （ More flexible ）.
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Not assigned is null.
Insert multiple pieces of data at the same time
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Mode two ： Insert the query results into the table .
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Update data

update…set…where…
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Modify multiple fields of a data at the same time
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Unsuccessful modification
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Delete data

delete…from…where…
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mysql8 New characteristics ： Calculated column

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Data type refinement （ On ）

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integer

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Floating point numbers 、 Fixed point number and bit type

1. Floating point type
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2. Fixed point number type
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3. A type of
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Date and time type

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Experience in development

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The result is 1970 year 1 month 1 Number 0 when 0 branch 0 The number of milliseconds from seconds to the time of writing this code

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本文为[88 year old programming with injury]所创，转载请带上原文链接，感谢
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