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Diffstat (limited to 'lib/impure/db_sqlite.nim')
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diff --git a/lib/impure/db_sqlite.nim b/lib/impure/db_sqlite.nim deleted file mode 100644 index f182ae65a..000000000 --- a/lib/impure/db_sqlite.nim +++ /dev/null @@ -1,650 +0,0 @@ -# -# -# Nim's Runtime Library -# (c) Copyright 2015 Andreas Rumpf -# -# See the file "copying.txt", included in this -# distribution, for details about the copyright. -# - -## A higher level `SQLite`:idx: database wrapper. This interface -## is implemented for other databases too. -## -## Basic usage -## =========== -## -## The basic flow of using this module is: -## -## 1. Open database connection -## 2. Execute SQL query -## 3. Close database connection -## -## Parameter substitution -## ---------------------- -## -## All ``db_*`` modules support the same form of parameter substitution. -## That is, using the ``?`` (question mark) to signify the place where a -## value should be placed. For example: -## -## .. code-block:: Nim -## -## sql"INSERT INTO my_table (colA, colB, colC) VALUES (?, ?, ?)" -## -## Opening a connection to a database -## ---------------------------------- -## -## .. code-block:: Nim -## -## import db_sqlite -## -## # user, password, database name can be empty. -## # These params are not used on db_sqlite module. -## let db = open("mytest.db", "", "", "") -## db.close() -## -## Creating a table -## ---------------- -## -## .. code-block:: Nim -## -## db.exec(sql"DROP TABLE IF EXISTS my_table") -## db.exec(sql"""CREATE TABLE my_table ( -## id INTEGER, -## name VARCHAR(50) NOT NULL -## )""") -## -## Inserting data -## -------------- -## -## .. code-block:: Nim -## -## db.exec(sql"INSERT INTO my_table (id, name) VALUES (0, ?)", -## "Jack") -## -## Larger example -## -------------- -## -## .. code-block:: nim -## -## import db_sqlite, math -## -## let db = open("mytest.db", "", "", "") -## -## db.exec(sql"DROP TABLE IF EXISTS my_table") -## db.exec(sql"""CREATE TABLE my_table ( -## id INTEGER PRIMARY KEY, -## name VARCHAR(50) NOT NULL, -## i INT(11), -## f DECIMAL(18, 10) -## )""") -## -## db.exec(sql"BEGIN") -## for i in 1..1000: -## db.exec(sql"INSERT INTO my_table (name, i, f) VALUES (?, ?, ?)", -## "Item#" & $i, i, sqrt(i.float)) -## db.exec(sql"COMMIT") -## -## for x in db.fastRows(sql"SELECT * FROM my_table"): -## echo x -## -## let id = db.tryInsertId(sql"""INSERT INTO my_table (name, i, f) -## VALUES (?, ?, ?)""", -## "Item#1001", 1001, sqrt(1001.0)) -## echo "Inserted item: ", db.getValue(sql"SELECT name FROM my_table WHERE id=?", id) -## -## db.close() -## -## -## Note -## ==== -## This module does not implement any ORM features such as mapping the types from the schema. -## Instead, a ``seq[string]`` is returned for each row. -## -## The reasoning is as follows: -## 1. it's close to what many DBs offer natively (char**) -## 2. it hides the number of types that the DB supports -## (int? int64? decimal up to 10 places? geo coords?) -## 3. it's convenient when all you do is to forward the data to somewhere else (echo, log, put the data into a new query) -## -## See also -## ======== -## -## * `db_odbc module <db_odbc.html>`_ for ODBC database wrapper -## * `db_mysql module <db_mysql.html>`_ for MySQL database wrapper -## * `db_postgres module <db_postgres.html>`_ for PostgreSQL database wrapper - -{.deadCodeElim: on.} # dce option deprecated - -import sqlite3 - -import db_common -export db_common - -type - DbConn* = PSqlite3 ## Encapsulates a database connection. - Row* = seq[string] ## A row of a dataset. `NULL` database values will be - ## converted to an empty string. - InstantRow* = PStmt ## A handle that can be used to get a row's column - ## text on demand. - -proc dbError*(db: DbConn) {.noreturn.} = - ## Raises a `DbError` exception. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## if not db.tryExec(sql"SELECT * FROM not_exist_table"): - ## dbError(db) - ## db.close() - var e: ref DbError - new(e) - e.msg = $sqlite3.errmsg(db) - raise e - -proc dbQuote*(s: string): string = - ## Escapes the `'` (single quote) char to `''`. - ## Because single quote is used for defining `VARCHAR` in SQL. - runnableExamples: - doAssert dbQuote("'") == "''''" - doAssert dbQuote("A Foobar's pen.") == "'A Foobar''s pen.'" - - result = "'" - for c in items(s): - if c == '\'': add(result, "''") - else: add(result, c) - add(result, '\'') - -proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string = - result = "" - var a = 0 - for c in items(string(formatstr)): - if c == '?': - add(result, dbQuote(args[a])) - inc(a) - else: - add(result, c) - -proc tryExec*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): bool {. - tags: [ReadDbEffect, WriteDbEffect].} = - ## Tries to execute the query and returns `true` if successful, `false` otherwise. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## if not db.tryExec(sql"SELECT * FROM my_table"): - ## dbError(db) - ## db.close() - assert(not db.isNil, "Database not connected.") - var q = dbFormat(query, args) - var stmt: sqlite3.PStmt - if prepare_v2(db, q, q.len.cint, stmt, nil) == SQLITE_OK: - let x = step(stmt) - if x in {SQLITE_DONE, SQLITE_ROW}: - result = finalize(stmt) == SQLITE_OK - -proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {. - tags: [ReadDbEffect, WriteDbEffect].} = - ## Executes the query and raises a `DbError` exception if not successful. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## try: - ## db.exec(sql"INSERT INTO my_table (id, name) VALUES (?, ?)", - ## 1, "item#1") - ## except: - ## stderr.writeLine(getCurrentExceptionMsg()) - ## finally: - ## db.close() - if not tryExec(db, query, args): dbError(db) - -proc newRow(L: int): Row = - newSeq(result, L) - for i in 0..L-1: result[i] = "" - -proc setupQuery(db: DbConn, query: SqlQuery, - args: varargs[string]): PStmt = - assert(not db.isNil, "Database not connected.") - var q = dbFormat(query, args) - if prepare_v2(db, q, q.len.cint, result, nil) != SQLITE_OK: dbError(db) - -proc setRow(stmt: PStmt, r: var Row, cols: cint) = - for col in 0'i32..cols-1: - setLen(r[col], column_bytes(stmt, col)) # set capacity - setLen(r[col], 0) - let x = column_text(stmt, col) - if not isNil(x): add(r[col], x) - -iterator fastRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## Executes the query and iterates over the result dataset. - ## - ## This is very fast, but potentially dangerous. Use this iterator only - ## if you require **ALL** the rows. - ## - ## **Note:** Breaking the `fastRows()` iterator during a loop will cause the - ## next database query to raise a `DbError` exception ``unable to close due - ## to ...``. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## for row in db.fastRows(sql"SELECT id, name FROM my_table"): - ## echo row - ## - ## # Output: - ## # @["1", "item#1"] - ## # @["2", "item#2"] - ## - ## db.close() - var stmt = setupQuery(db, query, args) - var L = (column_count(stmt)) - var result = newRow(L) - try: - while step(stmt) == SQLITE_ROW: - setRow(stmt, result, L) - yield result - finally: - if finalize(stmt) != SQLITE_OK: dbError(db) - -iterator instantRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): InstantRow - {.tags: [ReadDbEffect].} = - ## Similar to `fastRows iterator <#fastRows.i,DbConn,SqlQuery,varargs[string,]>`_ - ## but returns a handle that can be used to get column text - ## on demand using `[]`. Returned handle is valid only within the iterator body. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## for row in db.instantRows(sql"SELECT * FROM my_table"): - ## echo "id:" & row[0] - ## echo "name:" & row[1] - ## echo "length:" & $len(row) - ## - ## # Output: - ## # id:1 - ## # name:item#1 - ## # length:2 - ## # id:2 - ## # name:item#2 - ## # length:2 - ## - ## db.close() - var stmt = setupQuery(db, query, args) - try: - while step(stmt) == SQLITE_ROW: - yield stmt - finally: - if finalize(stmt) != SQLITE_OK: dbError(db) - -proc toTypeKind(t: var DbType; x: int32) = - case x - of SQLITE_INTEGER: - t.kind = dbInt - t.size = 8 - of SQLITE_FLOAT: - t.kind = dbFloat - t.size = 8 - of SQLITE_BLOB: t.kind = dbBlob - of SQLITE_NULL: t.kind = dbNull - of SQLITE_TEXT: t.kind = dbVarchar - else: t.kind = dbUnknown - -proc setColumns(columns: var DbColumns; x: PStmt) = - let L = column_count(x) - setLen(columns, L) - for i in 0'i32 ..< L: - columns[i].name = $column_name(x, i) - columns[i].typ.name = $column_decltype(x, i) - toTypeKind(columns[i].typ, column_type(x, i)) - columns[i].tableName = $column_table_name(x, i) - -iterator instantRows*(db: DbConn; columns: var DbColumns; query: SqlQuery, - args: varargs[string, `$`]): InstantRow - {.tags: [ReadDbEffect].} = - ## Similar to `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_, - ## but sets information about columns to `columns`. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## var columns: DbColumns - ## for row in db.instantRows(columns, sql"SELECT * FROM my_table"): - ## discard - ## echo columns[0] - ## - ## # Output: - ## # (name: "id", tableName: "my_table", typ: (kind: dbNull, - ## # notNull: false, name: "INTEGER", size: 0, maxReprLen: 0, precision: 0, - ## # scale: 0, min: 0, max: 0, validValues: @[]), primaryKey: false, - ## # foreignKey: false) - ## - ## db.close() - var stmt = setupQuery(db, query, args) - setColumns(columns, stmt) - try: - while step(stmt) == SQLITE_ROW: - yield stmt - finally: - if finalize(stmt) != SQLITE_OK: dbError(db) - -proc `[]`*(row: InstantRow, col: int32): string {.inline.} = - ## Returns text for given column of the row. - ## - ## See also: - ## * `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_ - ## example code - $column_text(row, col) - -proc unsafeColumnAt*(row: InstantRow, index: int32): cstring {.inline.} = - ## Returns cstring for given column of the row. - ## - ## See also: - ## * `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_ - ## example code - column_text(row, index) - -proc len*(row: InstantRow): int32 {.inline.} = - ## Returns number of columns in a row. - ## - ## See also: - ## * `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_ - ## example code - column_count(row) - -proc getRow*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## Retrieves a single row. If the query doesn't return any rows, this proc - ## will return a `Row` with empty strings for each column. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## doAssert db.getRow(sql"SELECT id, name FROM my_table" - ## ) == Row(@["1", "item#1"]) - ## doAssert db.getRow(sql"SELECT id, name FROM my_table WHERE id = ?", - ## 2) == Row(@["2", "item#2"]) - ## - ## # Returns empty. - ## doAssert db.getRow(sql"INSERT INTO my_table (id, name) VALUES (?, ?)", - ## 3, "item#3") == @[] - ## doAssert db.getRow(sql"DELETE FROM my_table WHERE id = ?", 3) == @[] - ## doAssert db.getRow(sql"UPDATE my_table SET name = 'ITEM#1' WHERE id = ?", - ## 1) == @[] - ## db.close() - var stmt = setupQuery(db, query, args) - var L = (column_count(stmt)) - result = newRow(L) - if step(stmt) == SQLITE_ROW: - setRow(stmt, result, L) - if finalize(stmt) != SQLITE_OK: dbError(db) - -proc getAllRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): seq[Row] {.tags: [ReadDbEffect].} = - ## Executes the query and returns the whole result dataset. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## doAssert db.getAllRows(sql"SELECT id, name FROM my_table") == @[Row(@["1", "item#1"]), Row(@["2", "item#2"])] - ## db.close() - result = @[] - for r in fastRows(db, query, args): - result.add(r) - -iterator rows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## Similar to `fastRows iterator <#fastRows.i,DbConn,SqlQuery,varargs[string,]>`_, - ## but slower and safe. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## for row in db.rows(sql"SELECT id, name FROM my_table"): - ## echo row - ## - ## ## Output: - ## ## @["1", "item#1"] - ## ## @["2", "item#2"] - ## - ## db.close() - for r in fastRows(db, query, args): yield r - -proc getValue*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): string {.tags: [ReadDbEffect].} = - ## Executes the query and returns the first column of the first row of the - ## result dataset. Returns `""` if the dataset contains no rows or the database - ## value is `NULL`. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## doAssert db.getValue(sql"SELECT name FROM my_table WHERE id = ?", - ## 2) == "item#2" - ## doAssert db.getValue(sql"SELECT id, name FROM my_table") == "1" - ## doAssert db.getValue(sql"SELECT name, id FROM my_table") == "item#1" - ## - ## db.close() - var stmt = setupQuery(db, query, args) - if step(stmt) == SQLITE_ROW: - let cb = column_bytes(stmt, 0) - if cb == 0: - result = "" - else: - result = newStringOfCap(cb) - add(result, column_text(stmt, 0)) - else: - result = "" - if finalize(stmt) != SQLITE_OK: dbError(db) - -proc tryInsertID*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 - {.tags: [WriteDbEffect], raises: [].} = - ## Executes the query (typically "INSERT") and returns the - ## generated ID for the row or -1 in case of an error. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## db.exec(sql"CREATE TABLE my_table (id INTEGER, name VARCHAR(50) NOT NULL)") - ## - ## doAssert db.tryInsertID(sql"INSERT INTO not_exist_table (id, name) VALUES (?, ?)", - ## 1, "item#1") == -1 - ## db.close() - assert(not db.isNil, "Database not connected.") - var q = dbFormat(query, args) - var stmt: sqlite3.PStmt - result = -1 - if prepare_v2(db, q, q.len.cint, stmt, nil) == SQLITE_OK: - if step(stmt) == SQLITE_DONE: - result = last_insert_rowid(db) - if finalize(stmt) != SQLITE_OK: - result = -1 - -proc insertID*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {.tags: [WriteDbEffect].} = - ## Executes the query (typically "INSERT") and returns the - ## generated ID for the row. - ## - ## Raises a `DbError` exception when failed to insert row. - ## For Postgre this adds ``RETURNING id`` to the query, so it only works - ## if your primary key is named ``id``. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## db.exec(sql"CREATE TABLE my_table (id INTEGER, name VARCHAR(50) NOT NULL)") - ## - ## for i in 0..2: - ## let id = db.insertID(sql"INSERT INTO my_table (id, name) VALUES (?, ?)", i, "item#" & $i) - ## echo "LoopIndex = ", i, ", InsertID = ", id - ## - ## # Output: - ## # LoopIndex = 0, InsertID = 1 - ## # LoopIndex = 1, InsertID = 2 - ## # LoopIndex = 2, InsertID = 3 - ## - ## db.close() - result = tryInsertID(db, query, args) - if result < 0: dbError(db) - -proc execAffectedRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {. - tags: [ReadDbEffect, WriteDbEffect].} = - ## Executes the query (typically "UPDATE") and returns the - ## number of affected rows. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## - ## # Records of my_table: - ## # | id | name | - ## # |----|----------| - ## # | 1 | item#1 | - ## # | 2 | item#2 | - ## - ## doAssert db.execAffectedRows(sql"UPDATE my_table SET name = 'TEST'") == 2 - ## - ## db.close() - exec(db, query, args) - result = changes(db) - -proc close*(db: DbConn) {.tags: [DbEffect].} = - ## Closes the database connection. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## let db = open("mytest.db", "", "", "") - ## db.close() - if sqlite3.close(db) != SQLITE_OK: dbError(db) - -proc open*(connection, user, password, database: string): DbConn {. - tags: [DbEffect].} = - ## Opens a database connection. Raises a `DbError` exception if the connection - ## could not be established. - ## - ## **Note:** Only the ``connection`` parameter is used for ``sqlite``. - ## - ## **Examples:** - ## - ## .. code-block:: Nim - ## - ## try: - ## let db = open("mytest.db", "", "", "") - ## ## do something... - ## ## db.getAllRows(sql"SELECT * FROM my_table") - ## db.close() - ## except: - ## stderr.writeLine(getCurrentExceptionMsg()) - var db: DbConn - if sqlite3.open(connection, db) == SQLITE_OK: - result = db - else: - dbError(db) - -proc setEncoding*(connection: DbConn, encoding: string): bool {. - tags: [DbEffect].} = - ## Sets the encoding of a database connection, returns `true` for - ## success, `false` for failure. - ## - ## **Note:** The encoding cannot be changed once it's been set. - ## According to SQLite3 documentation, any attempt to change - ## the encoding after the database is created will be silently - ## ignored. - exec(connection, sql"PRAGMA encoding = ?", [encoding]) - result = connection.getValue(sql"PRAGMA encoding") == encoding - -when not defined(testing) and isMainModule: - var db = open("db.sql", "", "", "") - exec(db, sql"create table tbl1(one varchar(10), two smallint)", []) - exec(db, sql"insert into tbl1 values('hello!',10)", []) - exec(db, sql"insert into tbl1 values('goodbye', 20)", []) - #db.query("create table tbl1(one varchar(10), two smallint)") - #db.query("insert into tbl1 values('hello!',10)") - #db.query("insert into tbl1 values('goodbye', 20)") - for r in db.rows(sql"select * from tbl1", []): - echo(r[0], r[1]) - for r in db.instantRows(sql"select * from tbl1", []): - echo(r[0], r[1]) - - db_sqlite.close(db) |