public abstract class Function extends Object
A subclass of org.sqlite.Function can be registered with Function.create() and called by the name it was given. All functions must implement xFunc(), which is called when SQLite runs the custom function.
Eg.Class.forName("org.sqlite.JDBC"); Connection conn = DriverManager.getConnection("jdbc:sqlite:"); Function.create(conn, "myFunc", new Function() { protected void xFunc() { System.out.println("myFunc called!"); } }); conn.createStatement().execute("select myFunc();");
Arguments passed to a custom function can be accessed using the protected functions provided. args() returns the number of arguments passed, while value_<type>(int) returns the value of the specific argument. Similarly a function can return a value using the result(<type>) function.
Aggregate functions are not yet supported, but coming soon.
Modifier and Type | Class and Description |
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static class |
Function.Aggregate
Provides an interface for creating SQLite user-defined aggregate functions.
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Constructor and Description |
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Function() |
Modifier and Type | Method and Description |
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protected int |
args()
Returns the number of arguments passed to the function.
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static void |
create(Connection conn,
String name,
Function f)
Registers a given function with the connection.
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static void |
destroy(Connection conn,
String name)
Removes a named function from the given connection.
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protected void |
error(String err)
Called by xFunc to throw an error.
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protected void |
result()
Called by xFunc to return a value.
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protected void |
result(byte[] value)
Called by xFunc to return a value.
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protected void |
result(double value)
Called by xFunc to return a value.
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protected void |
result(int value)
Called by xFunc to return a value.
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protected void |
result(long value)
Called by xFunc to return a value.
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protected void |
result(String value)
Called by xFunc to return a value.
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protected byte[] |
value_blob(int arg)
Called by xFunc to access the value of an argument.
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protected double |
value_double(int arg)
Called by xFunc to access the value of an argument.
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protected int |
value_int(int arg)
Called by xFunc to access the value of an argument.
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protected long |
value_long(int arg)
Called by xFunc to access the value of an argument.
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protected String |
value_text(int arg)
Called by xFunc to access the value of an argument.
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protected int |
value_type(int arg)
Called by xFunc to access the value of an argument.
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protected abstract void |
xFunc()
Called by SQLite as a custom function.
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public static final void create(Connection conn, String name, Function f) throws SQLException
conn
- The connection.name
- The name of the function.f
- The function to register.SQLException
public static final void destroy(Connection conn, String name) throws SQLException
conn
- The connection to remove the function from.name
- The name of the function.SQLException
protected abstract void xFunc() throws SQLException
SQLException
protected final int args() throws SQLException
SQLException
protected final void result(byte[] value) throws SQLException
value
- SQLException
protected final void result(double value) throws SQLException
value
- SQLException
protected final void result(int value) throws SQLException
value
- SQLException
protected final void result(long value) throws SQLException
value
- SQLException
protected final void result() throws SQLException
SQLException
protected final void result(String value) throws SQLException
value
- SQLException
protected final void error(String err) throws SQLException
err
- SQLException
protected final String value_text(int arg) throws SQLException
arg
- SQLException
protected final byte[] value_blob(int arg) throws SQLException
arg
- SQLException
protected final double value_double(int arg) throws SQLException
arg
- SQLException
protected final int value_int(int arg) throws SQLException
arg
- SQLException
protected final long value_long(int arg) throws SQLException
arg
- SQLException
protected final int value_type(int arg) throws SQLException
arg
- SQLException
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