# See the License for the specific language governing permissions and
# limitations under the License.
+# A native wrapper ove the postgres c api
module native_postgres is pkgconfig("libpq")
in "C header" `{
new nonfatal_error `{ return PGRES_NONFATAL_ERROR; `}
new fatal_error `{ return PGRES_FATAL_ERROR; `}
- fun is_ok: Bool `{return self == PGRES_TUPLES_OK || self == PGRES_COMMAND_OK; `}
+ fun is_ok: Bool `{
+ return !(self == PGRES_BAD_RESPONSE || self == PGRES_NONFATAL_ERROR || self == PGRES_FATAL_ERROR);
+ `}
redef fun to_s import NativeString.to_s `{
char * err = PQresStatus(self);
fun is_ok: Bool `{return self == CONNECTION_OK; `}
end
-extern class PGResult `{PGresult *`}
+extern class NativePGResult `{PGresult *`}
# Frees the memory block associated with the result
fun clear `{PQclear(self); `}
extern class NativePostgres `{PGconn *`}
# Connect to a new database using the conninfo string as a parameter
- new connectdb(conninfo: String) import String.to_cstring `{
+ new connectdb(conninfo: Text) import Text.to_cstring `{
PGconn * self = NULL;
- self = PQconnectdb(String_to_cstring(conninfo));
+ self = PQconnectdb(Text_to_cstring(conninfo));
return self;
`}
# Submits a query to the server and waits for the result returns the ExecStatustype of the query
- fun exec(query: String): PGResult import String.to_cstring `{
- PGresult *res = PQexec(self, String_to_cstring(query));
+ fun exec(query: Text): NativePGResult import Text.to_cstring `{
+ PGresult *res = PQexec(self, Text_to_cstring(query));
return res;
`}
# Prepares a statement with the given parameters
- fun prepare(stmt: String, query: String, nParams: Int):PGResult import String.to_cstring `{
+ fun prepare(stmt: String, query: String, nParams: Int): NativePGResult import String.to_cstring `{
const char * stmtName = String_to_cstring(stmt);
const char * queryStr = String_to_cstring(query);
PGresult * res = PQprepare(self, stmtName, queryStr, nParams, NULL);
return res;
`}
- fun exec_prepared(stmt: String, nParams: Int, values: Array[String], pLengths: Array[Int], pFormats: Array[Int], resultFormat: Int):PGResult import String.to_cstring, Array[String].[], Array[Int].[] `{
+ fun exec_prepared(stmt: String, nParams: Int, values: Array[String], pLengths: Array[Int], pFormats: Array[Int], resultFormat: Int): NativePGResult import String.to_cstring, Array[String].[], Array[Int].[] `{
const char * stmtName = String_to_cstring(stmt);
const char * paramValues[nParams];
int paramLengths[nParams];
--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2016 Guilherme Mansur<guilhermerpmansur@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Services to manipulate a Postgres database
+#
+# For more information, refer to the documentation of http://www.postgresql.org/docs/manuals/
+#
+# ### Usage example
+#
+# ~~~
+# class Animal
+# var name: String
+# var kind: String
+# var age: Int
+# end
+#
+# var animals = new Array[Animal]
+# var dog = new Animal("Lassy", "dog", 10)
+# var cat = new Animal("Garfield", "cat", 3)
+# var turtle = new Animal("George", "turtle", 123)
+#
+# animals.add(dog)
+# animals.add(cat)
+# animals.add(turtle)
+#
+# var db = new Postgres.open("dbname=postgres")
+#
+# assert db_is_open: not db.is_closed
+# assert create_table: db.create_table("IF NOT EXISTS animals (aname TEXT PRIMARY KEY, kind TEXT NOT NULL, age INT NOT NULL)") else print db.error
+#
+# for animal in animals do
+# assert insert: db.insert("INTO animals VALUES('{animal.name}', '{animal.kind}', {animal.age})") else print db.error
+# end
+#
+# var result = db.raw_execute("SELECT * FROM animals")
+# assert result.is_ok
+# assert drop_table: db.execute("DROP TABLE animals")
+# db.finish
+# assert db_is_closed: db.is_closed
+# ~~~
+module postgres
+
+private import native_postgres
+
+# A connection to a Postgres database
+class Postgres
+ private var native_connection: NativePostgres
+
+ var is_closed = true
+
+ # Open the connnection with the database using the `conninfo`
+ init open(conninfo: Text)
+ do
+ init(new NativePostgres.connectdb(conninfo))
+ if native_connection.status.is_ok then is_closed = false
+ end
+
+ # Close this connection with the database
+ fun finish
+ do
+ if is_closed then return
+
+ is_closed = true
+
+ native_connection.finish
+ end
+
+ fun prepare(stmt_name:String, query:String, num_params: Int):PGResult do return new PGResult(native_connection.prepare(stmt_name, query, num_params))
+
+ fun exec_prepared(stmt_name: String, num_params: Int, values: Array[String], param_lengths: Array[Int], param_formats: Array[Int], result_format: Int):PGResult do
+ return new PGResult(native_connection.exec_prepared(stmt_name, num_params, values, param_lengths, param_formats, result_format))
+ end
+
+ # Executes a `query` and returns the raw `PGResult`
+ fun raw_execute(query: Text): PGResult do return new PGResult(native_connection.exec(query))
+
+ # Execute the `sql` statement and returns `true` on success
+ fun execute(query: Text): Bool do return native_connection.exec(query).status.is_ok
+
+ # 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)
+
+ # The latest error message on the connection an empty string if none
+ fun error: String do return native_connection.error
+
+ # The status of this connection
+ fun is_valid: Bool do return native_connection.status.is_ok
+
+ # Resets the connection to the database
+ fun reset do native_connection.reset
+end
+
+# The result of a given query
+class PGResult
+ private var pg_result: NativePGResult
+
+ fun clear do pg_result.clear
+
+ # Returns the number of rows in the query result
+ fun ntuples:Int do return pg_result.ntuples
+
+ # Returns the number of columns in each row of the query result
+ fun nfields:Int do return pg_result.nfields
+
+ # Returns the ExecStatusType of a result
+ fun is_ok:Bool do return pg_result.status.is_ok
+
+ # Returns the field name of a given `column_number`
+ fun fname(column_number:Int):String do return pg_result.fname(column_number)
+
+ # Returns the column number associated with the `column_name`
+ fun fnumber(column_name:String):Int do return pg_result.fnumber(column_name)
+
+ # Returns a single field value of one row of the result at `row_number`, `column_number`
+ fun value(row_number:Int, column_number:Int):String do return pg_result.value(row_number, column_number)
+
+ # Tests wether a field specified by the `row_number` and `column_number` is null.
+ fun is_null(row_number:Int, column_number: Int): Bool do return pg_result.is_null(row_number, column_number)
+end
--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2016 Guilherme Mansur <guilhermerpmansur@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+module test_postgres_nity
+
+import postgresql::postgres
+
+var db = new Postgres.open("dbname=postgres")
+assert open_db: not db.is_closed else print db.error
+
+assert create_table: db.create_table("IF NOT EXISTS users (uname TEXT PRIMARY KEY, pass TEXT NOT NULL, activated INTEGER, perc FLOAT)") else
+ print db.error
+end
+
+assert insert1: db.insert("INTO users VALUES('Bob', 'zzz', 1, 77.7)") else
+ print db.error
+end
+
+assert insert2: db.insert("INTO users VALUES('Guilherme', 'xxx', 1, 88)") else
+ print db.error
+end
+
+var result = db.raw_execute("SELECT * FROM users")
+
+assert raw_exec: result.is_ok else print db.error
+
+assert postgres_nfields: result.nfields == 4 else print_error db.error
+assert postgres_fname: result.fname(0) == "uname" else print_error db.error
+assert postgres_isnull: result.is_null(0,0) == false else print_error db.error
+assert postgres_value: result.value(0,0) == "Bob" else print_error db.error
+
+assert drop_table: db.execute("DROP TABLE users") else print db.error
+
+db.finish
+
+assert db.is_closed else print db.error
nitlanguage / nit.git / commitdiff