fm:run-query

fm:run-query is used to invoke an SQL statement to retrieve data from the database.

SYNTAX

<fm:run-query interface=”dbinterface” query=”query” match="XPath" mode=”string”/>

The Interface and Query attributes are required as they tell FOX which query to use. Match tells FOX what to run the query against. The Mode attribute can be set to “purge-selected”, “purge-all”, “augment” or “add-to” and tells FOX what to do with the retrieved data.

CONCEPTS

The SQL is a statement defined in fm:query in the DBI with data transformation rules

NOTES ABOUT MATCH

e.g. <fm:run-query interface="dbint” query="query” match="/A/B/C"/>

• The run-query match clause is used to identify subject elements to run the SQL for
• The SQL statement will be executed for each subject element identified in the match
• If there are 50 “C” elements inside “/A/B” above, the SQL statement will be run 50 times
• If there are no “C” elements, the SQL statement will NOT RUN at all
• SQL bind variables are obtained relative to each subject element (“C” above)
• This is a powerful 4GL feature as one fm:run-query fires off 50 different questions (for each “C”)
• This technique is referred to as “Query Over”. Here we are querying over “C” elements
• When match is omitted, default match=”.”, this SQL runs once with the attach point as a subject

EXAMPLES

Example 1

Simple run query to fetch some company data

<fm:run-query interface="dbint-s29" query="qry-s29-companies"/>

Example 2

      Query to fetch data into the :{theme} DOM

<fm:run-query interface="dbint-s29" query="qry-s29-tran” match=":{theme}"/>