======= Dictionary Column Attributes =======
====== Description ======
When creating a column in a table using the dictionary methods, the information provided must confirm to the following specification. Each column created has a number of mandatory and optional parameters.

====== Basic Syntax ======
The basic syntax of the attributes is as follows: 

  * All the information for the column must occur on a single line. 
  * The line ending may be a newline or carriage return/newline combination. 
  * Each attribute must be separated by at least one tab or space. 
  * The attributes must be specified in the order below
      - Column Name
      - Meta Attributes
      - Optional Arguments
<code php>
/*
 * Correct syntax
 */
$flds = "
COL1 C(60) NOTNULL DEFAULT 'abc',
COL2 I8 NOTNULL DEFAULT 0
";

/*
 * Incorrect syntax
 */
$flds = "
COL1 
C(60) 
NOTNULL 
DEFAULT 'abc',
COL2 
I8 
NOTNULL
DEFAULT 0
";
</code>
=======  Attributes =====
===== Column Name =====
  * The column name must conform to any database specific standards related to naming and length. If the name contains spaces, then it should be surrounded by backticks '' `col with spaces` ''. Note that this is an internal designator, and does not represent the character used by the database in SQL statements.                                                          
===== Meta Attributes =====
  * The column attributes in terms of type and length **must** be specified in terms of ADODb [[v5:dictionary:metatype|metaType]] descriptions, not the database definition for the type.
===== Optional Arguments =====
The following optional arguments may also be assigned to the column, table or key. If the attribute is inappropriate for the operation or column type or not supported by the DBMS, it is ignored.

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** Usage: Column **
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==== AUTO or AUTOINCREMENT ====
Creates the column as auto-increment. Support for this varies from one database to another. Some databases designate a field with an auto-increment flag as the primary key, and most databases only allow a single column in a table to be designated as auto-increment.

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** Usage: Index **
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==== CONSTRAINT ====
Adds a constraint to column. The syntax for the constraint must be defined as required by the database.
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**Usage: Column**
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==== DEF or DEFAULT ====
** DEF ** indicates a default value for a column when a row is created. Some databases also require a field with a default value to be designated as NOT NULL, so that is automatically added to the column string. For dynamically created dates or timestsamps, see the options below.
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** Usage: Column **
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==== DEFDATE ====
Indicates if the column (metaType **D** or **T**) should be defaulted to current date when a column is created. This differs from the **DEFTIMESTAMP** option below in that it only contains the date portion of a timestamp.
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** Usage: Column **
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==== DEFTIMESTAMP ====
Indicates if the column (metaType **D** or **T**) should be defaulted to current timestamp when a column is created.
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**Usage: Column**
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==== ENUM ====
In databases that support the //**ENUM**// datatype, append a parenthesized, quoted list of enum values 
  ENUM('lions','tigers','halibut')
  
Note that you should not place a space between ENUM and the left parenthises ''(''

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**Usage: Column**
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==== INDEX ====
Creates a single column index using the same name as the column, with 'idx_' prepended to the name, e.g. a column of name ''column1'' will create an index of name ''idx_column1''.
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** Usage: Any **
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==== NOQUOTE ====
Prevents ADOdb from applying the normal quoting rules to tables, columns and indexes. For example, a column name that contains a special character such as  //**some-column**// will be automatically quoted to **//'some-column'//**. This tag prevents the behavior.
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** Usage: Column **
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==== NOTNULL ====
Flags the column so that a NULL value cannot be inserted. For columns that are Auto-Increment or a Primary Key, this option is often implied.
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**Usage: Column**
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==== PRIMARY or KEY ====
Indicates if the column is part of the [[wp>Unique Key|Primary Key]] of the table.
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** Usage: Column**
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==== UNIQUE ====
** UNIQUE ** is an option against a key and indicates that duplicate values across all columns in the key are not allowed.
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**Usage: Column **
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==== UNSIGNED ====
Creates an unsigned integer.