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Changing the maximum length of a varchar column?
...characters to 500 without losing the contents. I've dropped and re-created tables before but I've never been exposed to the alter statement which is what I believe I need to use to do this. I found the documentation here: ALTER TABLE (Transfact-SQL) however I can't make heads or tails of it.
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Why is a div with “display: table-cell;” not affected by margin?
I have div elements next to each other with display: table-cell; .
4 Answers
4
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How to create id with AUTO_INCREMENT on Oracle?
...acle 11g. However, you can model it easily with a sequence and a trigger:
Table definition:
CREATE TABLE departments (
ID NUMBER(10) NOT NULL,
DESCRIPTION VARCHAR2(50) NOT NULL);
ALTER TABLE departments ADD (
CONSTRAINT dept_pk PRIMARY KEY (ID));
CREATE SEQUENCE dept_seq STA...
What are the differences between a clustered and a non-clustered index?
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Clustered Index
Only one per table
Faster to read than non clustered as data is physically stored in index order
Non Clustered Index
Can be used many times per table
Quicker for insert and update operations than a clustered index
Both types of inde...
中文网（自研/维护）拓展 · App Inventor 2 中文网
...otherwise.
DatabasePath()
Returns the path to the database.
Delete(table,whereClause,bindParams)
Executes a SQL DELETE statement.
DeleteAsync(tag,table,whereClause,bindParams)
Executes a SQL DELETE statement, asynchronously.
DeleteDatabase()
Delete the database.
Execute(sql,bi...
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 ...
Add new column with foreign key constraint in one command
...to add the column and the foreign key constraint using two separate ALTER TABLE commands:
12 Answers
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Create table in SQLite only if it doesn't exist already
I want to create a table in a SQLite database only if doesn't exist already. Is there any way to do this? I don't want to drop the table if it exists, only create it if it doesn't.
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MySQL 'create schema' and 'create database' - Is there any difference
...EATE SCHEMA" command, and it served to introduce
multiple name spaces for table and view names. All tables and views were
created within a "schema". I do not know whether that version defined
some cross-schema access to tables and views, but I assume it did.
AFAIR, no product (at least back then)...
Colspan all columns
... td tag should span all columns (when the exact amount of columns in the table will be variable/difficult to determine when the HTML is being rendered)? w3schools mentions you can use colspan="0" , but it doesn't say exactly what browsers support that value (IE 6 is in our list to support).
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