sql:query
Executes a SQL query, returning the result as a map.
query($connection as javatype:java.sql.Connection, $table as xs:string, $columns as xs:string*) ➔ map(*)*
Arguments | |||
| $connection | javatype:java.sql.Connection | A JDBC database connection established using sql:connect |
| $table | xs:string | The name of a table in the database |
| $columns | xs:string* | A list of required column names, or '*' to select all columns in the table |
Result | map(*)* |
query($connection as javatype:java.sql.Connection, $table as xs:string, $columns as xs:string*, $predicate as xs:string) ➔ map(*)*
Arguments | |||
| $connection | javatype:java.sql.Connection | A JDBC database connection established using sql:connect |
| $table | xs:string | The name of a table in the database |
| $columns | xs:string* | A list of required column names, or '*' to select all columns in the table |
| $predicate | xs:string | A SQL expression suitable for inclusion in the WHERE clause |
Result | map(*)* |
Namespace
http://saxon.sf.net/sql
Notes on the Saxon implementation
Introduced in Saxon 9.9. Designed to supersede the extension instruction sql:query. The saxon9-sql.jar
file,
distributed alongside the main JAR file, must be added to the classpath when these SQL extension functions
are used.
Details
The function executes a SQL query. For convenience the query is split across three arguments $table
,
$columns
and $predicate
but the function simply concatenates these together to form
a SQL query which is then executed.
The 3-argument form of the function retrieves all the rows in a table (the effective predicate is TRUE
).
The value returned by the function is a sequence of maps. Each row in the query result is
represented by one map in this sequence. The map represents a row in the result using a string-valued key
to represent the column name, and an appropriately-typed atomic value to represent the value of the column.
A SQL NULL
value is represented by an empty sequence.
Note that the result is a sequence rather than an array. It can be converted to an array (for example,
for serializing in JSON) using the expression array{$result}
.
Example:
<out> <xsl:for-each select="sql:query($connection, 'book', ('date', 'title'), 'author = ''J. K. Rowling''')"> <book date="{?date}" title="{?title}"/> </xsl:for-each> </out>