system.db.runScalarPrepQuery
This function is used in Python Scripting.
Description​
Runs a prepared statement against a database connection just like the runPrepQuery function, but only returns the value from the first row and column. If no results are returned from the query, the special value None is returned.
Client Permission Restrictions​
Permission Type: Legacy Database Access
Client access to this scripting function is blocked to users that do not meet the role/zone requirements for the above permission type. This function is unaffected when run in the Gateway scope.
Syntax - Gateway​
system.db.runScalarPrepQuery(query, args, database, [tx])
Parameters​
| Type | Parameter | Description |
|---|---|---|
| String | query | A SQL query (typically a SELECT) to run as a prepared statement with placeholders (?) denoting where the arguments go, that should be designed to return one row and one column. |
| List[Any] | args | A list of arguments. Will be used in order to match each placeholder (?) found in the query. |
| String | database | The name of the database connection to execute against. |
| String | tx | A transaction identifier. If omitted, the query will be executed in its own transaction. [optional] |
Returns​
Any - The value from the first row and first column of the results. Returns None if no rows were returned.
Scope​
Gateway
Syntax - Vision and Perspective​
system.db.runScalarPrepQuery(query, args, [database], [tx])
Parameters​
| Type | Parameter | Description |
|---|---|---|
| String | query | A SQL query (typically a SELECT) to run as a prepared statement with placeholders (?) denoting where the arguments go, that should be designed to return one row and one column. |
| List[Any] | args | A list of arguments. Will be used in order to match each placeholder (?) found in the query. |
| String | database | The name of the database connection to execute against. If omitted or "", the project's default database connection will be used. [optional] |
| String | tx | A transaction identifier. If omitted, the query will be executed in its own transaction. [optional] |
Returns​
Any - The value from the first row and first column of the results. Returns None if no rows were returned.
Scope​
Vision Client, Perspective Session
Code Examples​
# This example searches for the user id of someone based on a typed in username.
name = event.source.parent.getComponent("User Search").text
result = system.db.runScalarPrepQuery("SELECT user_id FROM users WHERE username = ?", [name])
event.source.parent.getComponent("Text Field").data = result