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How to get last inserted row ID from WordPress database?
My WordPress plugin has a table with a AUTO_INCREMENT primary key field called ID. When a new row is inserted into the table, I'd like to get the ID value of the insertion.
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Joins are for lazy people?
...d that using joins is less efficient than making several requests and link tables in the code (C# or Java).
21 Answers
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Determine the data types of a data frame's columns
...- lapply(frame, class)
res_frame <- data.frame(unlist(res))
barplot(table(res_frame), main="Data Types", col="steelblue", ylab="Number of Features")
}
to produce a plot of all data types in your data frame. For the iris dataset we get the following:
data_types(iris)
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SELECT * WHERE NOT EXISTS
...
You didn't join the table in your query.
Your original query will always return nothing unless there are no records at all in eotm_dyn, in which case it will return everything.
Assuming these tables should be joined on employeeID, use the foll...
What is PAGEIOLATCH_SH wait type in SQL Server?
...stem.
In practice, this almost always happens due to large scans over big tables. It almost never happens in queries that use indexes efficiently.
If your query is like this:
Select * from <table> where <col1> = <value> order by <PrimaryKey>
, check that you have a composit...
How to alter a column's data type in a PostgreSQL table?
...entation here: http://www.postgresql.org/docs/current/interactive/sql-altertable.html
ALTER TABLE tbl_name ALTER COLUMN col_name TYPE varchar (11);
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Oracle的列操作(增加列,修改列,删除列)，包括操作多列 - 数据库(内核) - 清...
...(增加列,修改列,删除列)，包括操作多列增加一列： alter table emp4 add test varchar2(10);修改一列： alter table emp4 modify test varchar2(20);删除一列：alter 增加一列：
alter table emp4 add test varchar2(10);
修改一列：
alter table emp4 modify test va...
Combining “LIKE” and “IN” for SQL Server [duplicate]
...y, the IN statement creates a series of OR statements... so
SELECT * FROM table WHERE column IN (1, 2, 3)
Is effectively
SELECT * FROM table WHERE column = 1 OR column = 2 OR column = 3
And sadly, that is the route you'll have to take with your LIKE statements
SELECT * FROM table
WHERE column...
Using LIMIT within GROUP BY to get N results per group?
...LECT id, GROUP_CONCAT(year ORDER BY rate DESC) grouped_year
FROM yourtable
GROUP BY id
Result:
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| ID | GROUPED_YEAR |
-----------------------------------------------------------
| p01 | 2006,200...
Understand the “Decorator Pattern” with a real world example
...ant to have to recompile and reship every time. I'd want to add a row in a table in the backend or something that would easily take care of their requirement. Well said, @Stelios Adamantidis. I guess the patterns biggest strength though would be modifying 3rd-party classes then.
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