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Data Access Layer (DAL)
is created to simplify and formalize work with events. This will be
extremely helpful for those who don't know SQL. Also DAL allows for
a merge of events from different templates (see Add template to project
option) and transfer events from one project to
another.
Each table is presented as ASP class, all fields are ASP
variables declared in this class.
Variables/Arrays
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Variable/Array
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Description
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Table("TableName")
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Provides
access to a table.
Example:
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Value("FieldName")
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Provides
access to the field values. Value("FieldName") refers to the field
to be updated or added.
Example:
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dal.Table("Cars").Value("Make")
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If the field name contains only English alphabet letters, digits
and underscores (doesn't contain spaces and special characters),
starts with a letter and doesn't coincide with ASP reserved words,
you can also use the following notation to access the field:
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Param("FieldName")
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Provides
access to the field values. Param("FieldName") is used in the
WHERE clause of update query. This allows you to avoid the
confusion when the same field appears in the field list and in
WHERE clause.
Example:
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dal.Table("UsersTable").Param("FirstName")="Bob"
dal.Table("UsersTable").Value("FirstName")="Jim"
dal.Table("UsersTable").Update()
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The corresponding SQL query:
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Update UsersTable set 'FirstName'='Jim' where 'FirstName'='Bob'
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Methods
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Method
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Description
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Add()
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Inserts a new
record into the database.
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CustomQuery()
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Runs custom
SQL query.
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Delete()
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Deletes one or
more records from the database.
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DBLookup()
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Executes an
SQL query passed as a parameter and returns the first value of the
first entry or null if nothing is found.
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FetchByID()
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Selects one or
more records matching the condition.
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Query()
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Selects
records from database sorting data by orderby
field or fields and return
recordset.
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QueryAll()
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Selects all
records.
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TableName()
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Returns table
name. This function is used for complex query with calculated
fields or joined tables.
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Update()
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Updates one or
more records in the database.
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UsersTableName()
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Returns
properly formatted login table name.
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whereAdd()
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Adds new AND
condition to the existing WHERE clause.
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Remarks
You can use shortened DAL
notation:
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set dalCars=dal.Table("Cars")
set data=dalCars.Query(strWhereClause,"")
Response.Write data("Make")
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Examples
Before
deleting a record check if related records exist
Dynamic SQL Query
Redirect to user info edit
page
Show
data from master table on detail view/edit/add page
Show list of customer orders
Update multiple tables
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