v5:dictionary:column_attributes
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v5:dictionary:column_attributes [2016/03/20 23:22] – [PRIMARY] mnewnham | v5:dictionary:column_attributes [2022/09/02 04:11] (current) – [Column Name] backticks mnewnham | ||
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====== Description ====== | ====== 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. | 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. | ||
- | -------------------------------- | + | |
- | <WRAP right info 300px> | + | |
- | $fields is a string, not an array | + | |
- | </ | + | |
====== Basic Syntax ====== | ====== Basic Syntax ====== | ||
The basic syntax of the attributes is as follows: | The basic syntax of the attributes is as follows: | ||
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======= | ======= | ||
===== Column Name ===== | ===== Column Name ===== | ||
- | * The column name must conform to any database specific standards related to naming and length. | + | * The column name must conform to any database specific standards related to naming and length. |
- | + | ||
===== Meta Attributes ===== | ===== Meta Attributes ===== | ||
* The column attributes in terms of type and length **must** be specified in terms of ADODb [[v5: | * The column attributes in terms of type and length **must** be specified in terms of ADODb [[v5: | ||
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</ | </ | ||
==== AUTO or AUTOINCREMENT ==== | ==== 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. | + | 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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</ | </ | ||
==== CONSTRAINT ==== | ==== CONSTRAINT ==== | ||
+ | Adds a constraint to column. The syntax for the constraint must be defined as required by the database. | ||
-------------------------- | -------------------------- | ||
<WRAP right box 150px> | <WRAP right box 150px> | ||
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</ | </ | ||
==== DEF or DEFAULT ==== | ==== 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 | + | ** 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, |
--------------------------- | --------------------------- | ||
+ | <WRAP right box 150px> | ||
+ | ** Usage: Column ** | ||
+ | </ | ||
==== DEFDATE ==== | ==== 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. | ||
-------------------------- | -------------------------- | ||
+ | <WRAP right box 150px> | ||
+ | ** Usage: Column ** | ||
+ | </ | ||
==== DEFTIMESTAMP ==== | ==== DEFTIMESTAMP ==== | ||
+ | Indicates if the column (metaType **D** or **T**) should be defaulted to current timestamp when a column is created. | ||
-------------------------- | -------------------------- | ||
<WRAP right box 150px> | <WRAP right box 150px> | ||
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</ | </ | ||
==== ENUM ==== | ==== ENUM ==== | ||
- | In databases that support the ENUM datatype, append a parenthesized, | + | In databases that support the //**ENUM**// datatype, append a parenthesized, |
ENUM(' | ENUM(' | ||
| | ||
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----------------------------------- | ----------------------------------- | ||
+ | <WRAP right box 150px> | ||
+ | **Usage: Column** | ||
+ | </ | ||
==== INDEX ==== | ==== INDEX ==== | ||
+ | Creates a single column index using the same name as the column, with ' | ||
------------------------------- | ------------------------------- | ||
- | ==== KEY ==== | ||
- | -------------------------------- | + | <WRAP right box 150px> |
+ | ** Usage: Any ** | ||
+ | </ | ||
==== NOQUOTE ==== | ==== 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 // | ||
-------------------------------- | -------------------------------- | ||
<WRAP right box 150px> | <WRAP right box 150px> | ||
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</ | </ | ||
==== NOTNULL ==== | ==== 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. | ||
---------------------------- | ---------------------------- | ||
<WRAP right box 150px> | <WRAP right box 150px> | ||
- | **Usage: | + | **Usage: |
</ | </ | ||
- | ==== PRIMARY ==== | + | ==== PRIMARY |
+ | Indicates if the column is part of the [[wp> | ||
--------------------------- | --------------------------- | ||
<WRAP right box 150px> | <WRAP right box 150px> | ||
** Usage: Column** | ** Usage: Column** | ||
</ | </ | ||
- | Indicates if the column is part of the [[wp> | + | |
==== UNIQUE ==== | ==== UNIQUE ==== | ||
** UNIQUE ** is an option against a key and indicates that duplicate values across all columns in the key are not allowed. | ** 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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</ | </ | ||
==== UNSIGNED ==== | ==== UNSIGNED ==== | ||
+ | Creates an unsigned integer. |
v5/dictionary/column_attributes.1458512571.txt.gz · Last modified: 2017/04/21 11:28 (external edit)