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Postgresql - change the size of a varchar column to lower length
I have a question about the ALTER TABLE command on a really large table (almost 30 millions rows).
One of its columns is a varchar(255) and I would like to resize it to a varchar(40) .
Basically, I would like to change my column by running the following command:
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Permission denied for relation
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GRANT on the database is not what you need. Grant on the tables directly.
Granting privileges on the database mostly is used to grant or revoke connect privileges. This allows you to specify who may do stuff in the database if they have sufficient other permissions.
You want ins...
MySQL - Make an existing Field Unique
I have an already existing table with a field that should be unique but is not. I only know this because an entry was made into the table that had the same value as another, already existing, entry and this caused problems.
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How can I restore the MySQL root user’s full privileges?
... of the privileges from my MySQL root user, including the ability to alter tables. Is there some way I can restore this user to its original state (with all privileges)?
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How do I escape a reserved word in Oracle?
In TSQL I could use something like Select [table] from tablename to select a column named "table".
5 Answers
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Importing a CSV file into a sqlite3 database table using Python
...nge to 'sqlite:///your_filename.db'
cur = con.cursor()
cur.execute("CREATE TABLE t (col1, col2);") # use your column names here
with open('data.csv','r') as fin: # `with` statement available in 2.5+
# csv.DictReader uses first line in file for column headings by default
dr = csv.DictReader(...
Having both a Created and Last Updated timestamp columns in MySQL 4.0
I have the following table schema;
11 Answers
11
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Entity Framework. Delete all rows in table
How I can quickly remove all rows in table using Entity Framework?
21 Answers
21
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How do I create some kind of table of content in GitHub wiki?
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It is nicely demonstrated in the Table of Contents of the Markdown Cheatsheet.
##### Table of Contents
[Headers](#headers)
[Emphasis](#emphasis)
...snip...
<a name="headers"/>
## Headers
If you hover over a Header in a GitHub Markdown file...
How can I get enum possible values in a MySQL database?
...ou. It also strips the quotes from the values.
function get_enum_values( $table, $field )
{
$type = $this->db->query( "SHOW COLUMNS FROM {$table} WHERE Field = '{$field}'" )->row( 0 )->Type;
preg_match("/^enum\(\'(.*)\'\)$/", $type, $matches);
$enum = explode("','", $matches...