Drupal 7 module development and creation of a custom table (table) (hook_schema)

For details about how to create a module, see Drupal 7 module development and establishment.

If you want to support Chinese characters, the file format must be saved as UTF-8, no BOM

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To create a separate table for your module, you need to useHook_schema

Table Name: myform

Function my_first_module_schema () {$ schema ['myform'] = array ('description' => 'first Form ', 'fields' => array ('id' => array ('type' => 'serial', 'unsigned' => true, 'not null' => true, 'description' => 'auto-increment primary key'), 'title' => array ('type' => 'varchar ', 'length' => 255, 'Not null' => true, 'default' => '', 'description' => 'title ',), 'fullname' => array ('type' => 'varchar ', 'length' => 64, 'not null' => true, 'default' => '', 'description' => 'name',), 'email '=> array ('type' => 'varchar', 'length' => 255, 'Not null' => true, 'default' => '', 'description' => 'email ',), 'body' => array ('type' => 'text', 'not null' => false, 'SIZE' => 'Big ', 'serialize' => true, 'description' => 'message content',), 'timestamp' => array ('type' => 'int', 'not null' => true, 'default' => 0, 'description' => 'message time ',),), 'indexes' => array ('myform _ timestamp' => array ('timestamp'),), 'Primary key' => array ('id '),); return $ Schema ;}

For detailed usage of $ schema, refer to schema API

Description

String. Plain text format. Table description

Fields Field

Array. Describes the structure of a database table. Array ('fieldname' => Specification). For more information, see the "detail fields" section below.

Primary key

Array. Indicates one or more primary keywords.

'primary key' => array('id'),

Unique keys unique key

Array. ('Key name' => Specification)

Foreign keys foreign key

Array. ('Foreign key name' => Specification)

Specification Structure

Array (
'Table' => 'appearance name ',
'Columns' => array ('table field name' => 'external field name ')
)

  'foreign keys' => array(    'node_revision' => array(      'table' => 'node_revision',      'columns' => array('vid' => 'vid'),     ),    'node_author' => array(      'table' => 'users',      'columns' => array('uid' => 'uid'),     ),   ),

The above Code Description:

• The foreign key names are node_revision and node_author.
• Node_author associates the uid in this table with the uid in users.
  

Indexes Index

Array. ('Index name' => Specification ).

Specification structure: array ('field name 1', 'field name 2',...) can contain one or more

    'indexes' => array(      'myform_timestamp' => array('timestamp'),    ),

The above Code indicates that the timestamp is indexed and the index name is myform_timestamp.

Fields 

• Description
  Field description
  
  
• Type
  Field type. Common types include 'Char ', 'varchar', 'text', 'blob ', 'int', 'float', 'numeric', 'serial ', most types automatically correspond to a data type.
  Use Serial to specify an auto-increment field. MySQL automatically interprets it as int auto_increment.
  
  
• Mysql_type,Pgsql_type,Sqlite_type, Etc.
  If you want to use an unofficial data type, you can specify a type for each database. In this case, you do not need to use the type parameter, but an error occurs when the database type is not specified. A writable solution is to use text as a backup in type.
  
  For example, type does not have the date and datetime types in MySQL. Here you can define 'mysql _ type' => 'date', 'mysql _ type' => 'datetime, an error occurs here. In this case, you need to write the int type first.
  
  
• Serialize
  Boolean value, indicating whether the field will be stored as a serialized string
  
  
• Size
  Data dimensions include tiny, small, medium, normal, and big. The default value is normal.
  For MySQL tables, see databaseschema_mysql: getfieldtypemap.
  
  

  MySQL size table

  	Tiny	Small	Medium	Normal	Big
  Varchar				Varchar
  Char				Char
  Text	Tinytext	Tinytext	Mediumtext	Text	Longtext
  Serial	Tinyint	Smallint	Mediumint	Int	Bigint
  Int	Tinyint	Smallint	Mediumint	Int	Bigint
  Float	Float	Float	Float	Float	Double
  Numeric				Decimal
  Blob				Blob	Longblob

  
  
  
• Not null
  If true, this field cannot be null ). The default value is false.
  
  
• Default
  The default value of this field. Note the differences between '', '0' and 0.
  
  
• Length
  This attribute is only applicable to Char, varchar, or text. Other types are ignored.
  
  
• Unsigned
  Boolean value. It only indicates whether int, float, and numeric are signed. Other types are ignored. The default value is false.
  
  
• Precision,Scale
  Only for the numeric type. Other types are ignored. The two values must be written.
  Precision is the total number of digits before and after the decimal point
  Scale is the number on the right of the decimal point.
  
  
• Binary
  Boolean value. MySQL sorts the char, varchar, and text types in case-sensitive binary order. It is invalid for other databases that are case-sensitive by default.
  Example:
  If binary = true, A and A are sorted by ASCII code, and a is before.
  If binarry = false, A is sorted before.

For more data type definitions, refer to: Data Types Drupal converts different databases to corresponding SQL

MySQL common types

• Auto-Increment(Auto_increment)
  
  

  'Id' => array ('type' => 'serial', 'unsigned' => true, 'not null' => true, 'description' => 'auto-increment primary key '),

  
  
  
• Date type(Date, time, datetime, timestamp)
  
  

  'Timestamp' => array ('type' => 'int', 'not null' => true, 'default' => 0, 'description' => 'message time ',),

Reference: Drupal module development example: Basic Application of forms



Drupal 7 module development and creation of a custom table (table) (hook_schema)