# This file is part of NIT ( http://www.nitlanguage.org ).
#
-# Copyright 2013 Guillaume Auger <jeho@resist.ca>
-#
+# Copyright 201 Alexis Laferrière <alexis.laf@xymus.net>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# See the License for the specific language governing permissions and
# limitations under the License.
+# Services to manipulate a Sqlite3 database
+#
+# For more information, refer to the documentation of http://www.sqlite.org/docs.html
module sqlite3
-in "C header" `{
- #include "sqlite3.h"
- struct Data{
- sqlite3 *ppDb;
- sqlite3_stmt * stmt;
- };
-
-`}
-
-extern Sqlite3 `{struct Data*`}
- new `{
- struct Data* data = malloc(sizeof(data));
- return data;
- `}
-
- fun destroy do close
-
- fun open(filename : String) import String::to_cstring`{
- sqlite3_open(String_to_cstring(filename), &recv->ppDb);
- `}
-
- fun close `{
- sqlite3_close(( recv)->ppDb);
- free(recv);
- `}
-
- fun exec(sql : String): Int import String::to_cstring `{
- struct Data * data = recv;
- return sqlite3_exec(data->ppDb, String_to_cstring(sql), 0, 0, 0);
- `}
-
- fun prepare(sql : String) import String::to_cstring `{
- struct Data * data = recv;
- int ret = sqlite3_prepare_v2(data->ppDb, String_to_cstring(sql), -1, &(data->stmt), 0);
- `}
-
- fun step: Int `{
- return sqlite3_step(recv->stmt);
- `}
-
- fun column_name(i: Int) : String import String::from_cstring `{
- const char * name = (sqlite3_column_name(recv->stmt, i));
- if(name == NULL){
- name = "";
- }
- char * ret = (char *) name;
- return new_String_from_cstring(ret);
- `}
-
- fun column_bytes(i: Int) : Int `{
- return sqlite3_column_bytes(recv->stmt, i);
- `}
-
- fun column_double(i: Int) : Float `{
- return sqlite3_column_double(recv->stmt, i);
- `}
-
- fun column_int(i: Int) : Int `{
- return sqlite3_column_int(recv->stmt, i);
- `}
-
- fun column_text(i: Int) : String import String::from_cstring `{
- char * ret = (char *) sqlite3_column_text(recv->stmt, i);
- if( ret == NULL ){
- ret = "";
- }
- return new_String_from_cstring(ret);
- `}
-
- fun column_type(i: Int) : Int `{
- return sqlite3_column_type(recv->stmt, i);
- `}
-
- # fun column_blob(i : Int) : String `{
- # TODO
- # `}
-
- fun column_count: Int `{
- return sqlite3_column_count(recv->stmt);
- `}
-
- fun last_insert_rowid: Int `{
- return sqlite3_last_insert_rowid(recv->ppDb);
- `}
-
- fun get_error : Int import String::from_cstring `{
- return sqlite3_errcode(recv->ppDb);
- `}
-
- fun get_error_str : String import String::from_cstring `{
- char * err =(char *) sqlite3_errmsg(recv->ppDb);
- if(err == NULL){
- err = "";
- }
- return new_String_from_cstring(err);
- `}
+private import native_sqlite3
+import standard
+
+# A connection to a Sqlite3 database
+class Sqlite3DB
+ private var native_connection: NativeSqlite3
+
+ # Is this connection to the DB open?
+ var is_open = false
+
+ # All `Statement` opened from this connection that must be closed with this connection
+ private var open_statements = new Array[Statement]
+
+ # Open a connection to the database file at `path`
+ init open(path: Text)
+ do
+ native_connection = new NativeSqlite3.open(path.to_s)
+ if native_connection.is_valid then is_open = true
+ end
+
+ # Close this connection to the DB and all open statements
+ fun close
+ do
+ is_open = false
+
+ # close open statements
+ for stmt in open_statements do if stmt.is_open then
+ stmt.close
+ end
+
+ native_connection.close
+ end
+
+ # Prepare and return a `Statement`, return `null` on error
+ fun prepare(sql: Text): nullable Statement
+ do
+ var native_stmt = native_connection.prepare(sql.to_s)
+ if native_stmt == null then return null
+
+ var stmt = new Statement(native_stmt)
+ open_statements.add stmt
+ return stmt
+ end
+
+ # Execute the `sql` statement and return `true` on success
+ fun execute(sql: Text): Bool
+ do
+ var err = native_connection.exec(sql.to_s)
+ return err.is_ok
+ end
+
+ # Create a table on the DB with a statement beginning with "CREATE TABLE ", followed by `rest`
+ #
+ # This method does not escape special characters.
+ fun create_table(rest: Text): Bool do return execute("CREATE TABLE " + rest)
+
+ # Insert in the DB with a statement beginning with "INSERT ", followed by `rest`
+ #
+ # This method does not escape special characters.
+ fun insert(rest: Text): Bool do return execute("INSERT " + rest)
+
+ # Replace in the DB with a statement beginning with "REPLACE", followed by `rest`
+ #
+ # This method does not escape special characters.
+ fun replace(rest: Text): Bool do return execute("REPLACE " + rest)
+
+ # Select from the DB with a statement beginning with "SELECT ", followed by `rest`
+ #
+ # This method does not escape special characters.
+ fun select(rest: Text): nullable Statement do return prepare("SELECT " + rest)
+
+ # TODO add more prefix here as needed
+
+ # The latest error message, or `null` if there is none
+ fun error: nullable String
+ do
+ if not native_connection.is_valid then
+ var err = sys.sqlite_open_error
+ if err == null then return null
+ return err.to_s
+ end
+
+ var err = native_connection.error
+ if err.is_ok then return null
+ return err.to_s
+ end
+end
+
+# A prepared Sqlite3 statement, created from `Sqlite3DB::prepare` or `Sqlite3DB::select`
+class Statement
+ private var native_statement: NativeStatement
+
+ private init(ns: NativeStatement) do self.native_statement = ns
+
+ # Is this statement usable?
+ var is_open = true
+
+ # Close and finalize this statement
+ fun close
+ do
+ is_open = false
+ native_statement.finalize
+ end
+
+ # Reset this statement and return a `StatementIterator` to iterate over the result
+ fun iterator: StatementIterator
+ do
+ native_statement.reset
+ native_statement.step
+ return new StatementIterator(self)
+ end
+end
+
+class StatementRow
+ # Statement linked to `self`
+ var statement: Statement
+
+ private init(s: Statement) do self.statement = s
+
+ # Number of entries in this row
+ #
+ # require: `self.statement.is_open`
+ fun length: Int
+ do
+ assert statement_closed: statement.is_open
+
+ return statement.native_statement.column_count
+ end
+
+ # Returns the `i`th entry on this row
+ fun [](i: Int): StatementEntry do return new StatementEntry(statement, i)
+end
+
+# An entry on a `StatementRow`
+class StatementEntry
+ # Statement linked to `self`
+ var statement: Statement
+
+ private var index: Int
+
+ private init(s: Statement, i: Int)
+ do
+ self.statement = s
+ self.index = i
+ end
+
+ # Name of the column
+ #
+ # require: `self.statement.is_open`
+ fun name: String is cached do
+ assert statement_closed: statement.is_open
+
+ return statement.native_statement.column_name(index)
+ end
+
+ # Get the value of this entry according to its Sqlite type
+ #
+ # require: `self.statement.is_open`
+ fun value: nullable Sqlite3Data
+ do
+ assert statement_closed: statement.is_open
+
+ var data_type = statement.native_statement.column_type(index)
+ if data_type.is_integer then return to_i
+ if data_type.is_float then return to_f
+ if data_type.is_blob then return to_blob
+ if data_type.is_null then return null
+ if data_type.is_text then return to_s
+ abort
+ end
+
+ # Get this entry as `Int`
+ #
+ # If the Sqlite type of this entry is not an integer, it will be `CAST` to
+ # integer. If `null`, returns 0.
+ #
+ # require: `self.statement.is_open`
+ fun to_i: Int
+ do
+ assert statement_closed: statement.is_open
+
+ return statement.native_statement.column_int(index)
+ end
+
+ # Get this entry as `Float`
+ #
+ # If the Sqlite type of this entry is not a floating point, it will be `CAST`
+ # to float. If `null`, returns 0.0.
+ #
+ # require: `self.statement.is_open`
+ fun to_f: Float
+ do
+ assert statement_closed: statement.is_open
+
+ return statement.native_statement.column_double(index)
+ end
+
+ # Get this entry as `String`
+ #
+ # If the Sqlite type of this entry is not text, it will be `CAST` to text.
+ # If null, returns an empty string.
+ #
+ # require: `self.statement.is_open`
+ redef fun to_s
+ do
+ assert statement_closed: statement.is_open
+
+ var native_string = statement.native_statement.column_text(index)
+ if native_string.address_is_null then return ""
+ return native_string.to_s_with_copy
+ end
+
+ # Get this entry as `Blob`
+ #
+ # If the Sqlite type of this entry is not a blob, it will be `CAST` to text.
+ # If null, returns a NULL pointer.
+ #
+ # require: `self.statement.is_open`
+ fun to_blob: Blob
+ do
+ assert statement_closed: statement.is_open
+
+ # By spec, we must get the pointer before the byte count
+ var pointer = statement.native_statement.column_blob(index)
+ var length = statement.native_statement.column_bytes(index)
+
+ return new Blob(pointer, length)
+ end
+end
+
+# Iterator over the rows of a statement result
+class StatementIterator
+ super Iterator[StatementRow]
+
+ # Statement linked to `self`
+ var statement: Statement
+
+ private init(s: Statement)
+ do
+ self.statement = s
+ self.item = new StatementRow(s)
+ end
+
+ redef var item: StatementRow
+
+ redef var is_ok = true
+
+ # require: `self.statement.is_open`
+ redef fun next
+ do
+ assert statement_closed: statement.is_open
+
+ var err = statement.native_statement.step
+ if err.is_row then
+ is_ok = true
+ else if err.is_done then
+ # Clean complete
+ is_ok = false
+ else
+ # error
+ # FIXME do something with the error?
+ is_ok = false
+ end
+ end
+end
+
+# A data type supported by Sqlite3
+interface Sqlite3Data end
+
+redef universal Int super Sqlite3Data end
+redef universal Float super Sqlite3Data end
+redef class String
+ super Sqlite3Data
+
+ # Return `self` between `'`s and escaping any extra `'`
+ #
+ # assert "'; DROP TABLE students".to_sql_string == "'''; DROP TABLE students'"
+ fun to_sql_string: String
+ do
+ return "'{self.replace('\'', "''")}'"
+ end
+end
+
+# A Sqlite3 blob
+class Blob
+ super Sqlite3Data
+
+ private init(pointer: Pointer, length: Int)
+ do
+ self.pointer = pointer
+ self.length = length
+ end
+
+ var pointer: Pointer
+ var length: Int
end
nitlanguage / nit.git / blobdiff