The "database" Property
The "database" property defines a database as the data source. It has the following sub properties:
| Element | Description |
|---|---|
| "connection" | The name of a database connection |
| "execute" | Array of SQL statements to be executed before data retrieval (optional) |
| "keyfield" | The key field for the main table (optional) |
| "maintable" | The main table for this application (optional) |
| "orderby" | A fixed SQL orderby clause for the application (optional) |
| "sql" | The SQL statement for retrieving data |
Data From a Database
This model fetches records containing Customer, City, and Country from a Customer table in an SQL database:
Example
{
"database": {
"connection": "mysql",
"sql" :
"SELECT CustomerName, City, Country FROM Customers",
"orderby" : "CustomerName"
}
}
Filter Restrictions
To allow users to filter data, you can add filter information to the model:
"filteritems" : [
{"item" : "CustomerName", "label" : "Customer"},
{"item" : "City"},
{"item" : "Country"}]
Sorting Restrictions
To allow users to sort data, you can add sort information to the model:
"sortitems" : [
{"item" : "CustomerName", "label" : "Customer"},
{"item" : "City"},
{"item" : "Country"}]
Update Restrictions
To allow users to update data, you can include update information in the model:
Example
"updateItems" : [
{"item" : "CustomerName"},
{"item" : "Address"},
{"item" : "PostalCode"},
{"item" : "City"},
{"item" : "Country"}]
By default, AppML will let you filter, sort, or update data, only it is specified in the model.
Database Connections
Database connections are defined in appml_config.php:
appml_config.php
<?php echo("Access Forbidden");exit();?>
{
"dateformat" : "yyyy-mm-dd",
"databases": [
{
"connection" : "mysql",
"host"
: "127.0.0.1:3306",
"dbname" : "Northwind",
"username"
: "myUserId",
"password" : "myPassword"
},
{
"connection" : "googleDB",
"host" :
"192.168.1.1:3306",
"dbname" : "Northwind",
"username"
: "myUserId",
"password" : "myPassword"
},
{
"connection" : "amazonDB",
"host" :
"mydbinstance.amazon.com:3306",
"dbname" : "Northwind",
"username" : "myUserId",
"password" : "myPassword"
},
{
"connection" : "azureDB",
"host" :
"azure.cloudapp.net",
"dbname" : "Northwind",
"username" :
"myUserId",
"password" : "myPassword"
}
]
}
The configuration file can contain many database connections.
Creating Databases
Since AppML allows you to execute SQL statements before the application is started, you can use this to create a database if needed:
Model
{
"database" : {
"connection" : "myCDs",
"execute" : [
"DROP
TABLE IF EXISTS CD_Catalog",
"CREATE TABLE IF NOT EXISTS CD_Catalog (CDID
INT NOT NULL AUTO_INCREMENT,PRIMARY KEY (CDID),Title NVARCHAR(255),Artist NVARCHAR(255),Country NVARCHAR(255),Price
NUMBER)"
]
}}
Perfect for rapid prototyping!