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SQL Server Regular expressions in T-SQL
... of people to SQL Server. The "people" are from the [Application].[People] table in the [WideWorldImporters] sample database. They get passed to the R engine as a dataframe named InputDataSet. R uses the grepl function with the "not" operator (exclamation point!) to find which people have email addr...
SQL to find the number of distinct values in a column
...aggregate function:
SELECT COUNT(DISTINCT column_name) AS some_alias FROM table_name
This will count only the distinct values for that column.
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MySQL - Rows to Columns
...e of terms that I'll use for the rest of this post. This will be the base table:
select * from history;
+--------+----------+-----------+
| hostid | itemname | itemvalue |
+--------+----------+-----------+
| 1 | A | 10 |
| 1 | B | 3 |
| 2 | A | ...
Rails 4: List of available datatypes
... is not set to use :sql, then your schema.rb file wont be able to dump the table that uses types like :json. The schema will still be dumped for the tables that use default types but you'll see a comment for the table with special types like, "could not dump table...". Look here to set the schema_fo...
Why would you use Expression rather than Func?
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@bertl Delegate is what CPU sees (executable code of one architecture), Expression is what compiler sees (merely another format of source code, but still source code).
– codewarrior
May 5 '17 at 9:22
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What are best practices that you use when writing Objective-C and Cocoa? [closed]
...lass? That is especially true in an environment like the iPhone.
3.5) In table cells, make every element (including the cell itself) opaque for performance. That means setting the appropriate background color in everything.
3.6) When using an NSURLConnection, as a rule you may well want to implem...
How to delete from multiple tables in MySQL?
I am trying to delete from a few tables at once. I've done a bit of research, and came up with this
7 Answers
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Sequelize Unknown column '*.createdAt' in 'field list'
...he error is that you have timestamps enabled in sequelize, but your actual table definitions in the DB do not contain a timestamp column.
When you do user.find it will just do SELECT user.*, which only takes the columns you actually have. But when you join, each column of the joined table will be a...
Disable ONLY_FULL_GROUP_BY
...For instance, insert (below the [mysqld] section) sql_mode = "STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
– Vincent Pazeller
Nov 22 '16 at 10:44
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Stored procedure slow when called from web, fast from Management Studio
... change:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
SELECT * FROM Table WHERE ID = @param1
to:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
DECLARE @param1a int
SET @param1a = @param1
SELECT * FROM Table WHERE ID = @param1a
Seems strange, but it fixed my problem.
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