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How to check if a column exists in a SQL Server table?
...HERE Name = N'columnName'
AND Object_ID = Object_ID(N'schemaName.tableName'))
BEGIN
-- Column Exists
END
Martin Smith's version is shorter:
IF COL_LENGTH('schemaName.tableName', 'columnName') IS NOT NULL
BEGIN
-- Column Exists
END
...
SQL Server add auto increment primary key to existing table
As the title, I have an existing table which is already populated with 150000 records. I have added an Id column (which is currently null).
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Random record in ActiveRecord
I'm in need of getting a random record from a table via ActiveRecord. I've followed the example from Jamis Buck from 2006 .
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How to get line count of a large file cheaply in Python?
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is wccount in this table for the subprocess shell wc tool?
– Anentropic
Nov 11 '15 at 18:05
1
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INNER JOIN ON vs WHERE clause
...It is generally considered more readable, especially when you join lots of tables.
It can also be easily replaced with an OUTER JOIN whenever a need arises.
The WHERE syntax is more relational model oriented.
A result of two tables JOINed is a cartesian product of the tables to which a filter is ...
Changing the size of a column referenced by a schema-bound view in SQL Server
...SDN:
SCHEMABINDING
Binds the view to the schema of the underlying table or tables. When
SCHEMABINDING is specified, the base
table or tables cannot be modified in
a way that would affect the view
definition. The view definition itself
must first be modified or dropped to
remove ...
Can I add a UNIQUE constraint to a PostgreSQL table, after it's already created?
I have the following table:
4 Answers
4
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How to join (merge) data frames (inner, outer, left, right)
...f performance is a major issue for you, you should also look into the data.table package - that's a whole new set of join syntax, but it's radically faster than anything we're talking about here.
– Matt Parker
Feb 12 '13 at 16:22
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What is the difference between a stored procedure and a view?
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A view represents a virtual table. You can join multiple tables in a view and use the view to present the data as if the data were coming from a single table.
A stored procedure uses parameters to do a function... whether it is updating and inserting ...
Inner join vs Where
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No! The same execution plan, look at these two tables:
CREATE TABLE table1 (
id INT,
name VARCHAR(20)
);
CREATE TABLE table2 (
id INT,
name VARCHAR(20)
);
The execution plan for the query using the inner join:
-- with inner join
EXPLAIN PLAN FOR
SELECT * FRO...