Select

Kalipso - Form - Actions - Actions Description - Group Database - Select

Selects one or more records from the specified Database Table.

Action available for the following operating systems:

Parameters

SELECT

• From - Database Table where to retrieve the records from.

• Function - Function applied to the specified column. For further information about this parameter, please consult the documentation of your Database or SQLite if you're working off-line.

  • AVG - Returns the average value of the specified Column.

  • COUNT - Returns the number of records.

  • MAX - Returns the maximum value of the specified Column.

  • MIN - Returns the minimum value of the specified Column.

  • SUM - Returns the sum of the values of the specified Column.

• Column - Column to be retrieved.

• Into <target> - Control or Variable where to store the retrieved value.

• Nth From - Table where to retrieve the records from.

• Nth Function <unquoted string> - Function applied to the specified column. For further information about this parameter, please consult the documentation of your Database or SQLite if you're working off-line.

• Nth Column <unquoted string> - Column to be retrieved.

• Nth Into <unquoted string> - Control or Variable where to store the retrieved value.

• Ignore Database Masks - If you've defined a Mask for the specified Column in the Table properties and:

  • This option is checked - The value is return the Kalipso format.

  • This option is unchecked - The value is returned with the Mask format.

• Clear Data When No Record is Returned - If this option is checked and no record is returned, all the targets (Into parameter) are cleared.

• Where <Kalipso Filter> or <string> - Condition to specify which records should be retrieved. Check Expressions chapter for more information about Kalipso Filter and String expressions.

Usage

This function generates a Select operation that exists in every SQL database, and is used to query the database and retrieve data according to one ore more conditions.

Consider the following Database Table, and the following Variables:

Products
Code	Name	Stock
1	Coca Cola	100
2	Pepsi Cola	200
3	Pork Chops	300

Code	Name	Stock
VAR(0)	String	Kalipso
VAR(1)	Numeric	0
VAR(2)	String	Kalipso1

Consider that column Code is Numeric, column Name is String and column Stock is Numeric. Note that the table showing variables isn't a database table, its purpose is to show only the values and type of each variable.

Example 1

From	Function	Column	Into
Products	<none>	Code	VAR(0)
Products	<none>	Name	VAR(1)
Products	<none>	Stock	VAR(2)
Where	FIELD(Products,Code)=001
Clear Data	Yes

Result:

Variable	Type	Value
VAR(0)	String	1
VAR(1)	Numeric	Coca Cola
VAR(2)	String	100

Example 2

From	Function	Column	Into
Products	AVG	Code	VAR(0)
Products	<none>	Name	VAR(1)
Products	SUM	Stock	VAR(2)
Where	FIELD(Products,Code)=004
Clear Data	Yes

Result:

Variable	Type	Value
VAR(0)	Numeric
VAR(1)	String
VAR(2)	Numeric

Example 3

From	Function	Column	Into
Products	<none>	Code	VAR(0)
Products	<none>	Name	VAR(1)
Products	<none>	Stock	VAR(2)
Where	FIELD(Products,Code)=004
Clear Data	No

Result:

Variable	Type	Value
VAR(0)	String	kalipso
VAR(1)	Numeric	0
VAR(2)	String	kalipso1

Example 4

From	Function	Column	Into
Products	AVG	Code	VAR(0)
Products	<none>	Name	VAR(1)
Products	SUM	Stock	VAR(2)
Where	FIELD(Products,Code)=004
Clear Data	No

Result:

Variable	Type	Value
VAR(0)	Numeric
VAR(1)	String
VAR(2)	Numeric

In this example, the option Clear Data is disabled but are used functions AVG and SUM , and because of that, this operation return on record, therefore types are enforced.

Example 5

From	Function	Column	Into
Products	SUM	Stock	VAR(2)
Where	FIELD(Products,Code)<>0
Clear Data	Yes

Result:

Variable	Type	Value
VAR(0)	String	kalipso
VAR(1)	Numeric	0
VAR(2)	Numeric	600

Example 6

From	Function	Column	Into
Products	MIN	Code	VAR(0)
Products	COUNT	Name	VAR(1)
Products	SUM	Stock	VAR(2)
Where	FIELD(Products,Code)<> ""
Clear Data	No

Result:

Variable	Type	Value
VAR(0)	Numeric	1
VAR(1)	String	3
VAR(2)	Numeric	600

Notice that, as you can see in the examples above, Variable types are enforced, except if there is no result of the select operation and parameter Clear Data isn't checked.

When you specify more than one condition in Where parameter, the operator used between the conditions is "AND" or "OR".

You can use the RECORDCOUNT Keyword to know how many records where returned.