# # # 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. ## ## See also: `db_odbc `_, `db_postgres `_, ## `db_mysql `_. ## ## 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 myTable (colA, colB, colC) VALUES (?, ?, ?)" ## ## Examples ## -------- ## ## Opening a connection to a database ## ================================== ## ## .. code-block:: Nim ## import db_sqlite ## let db = open("localhost", "user", "password", "dbname") ## db.close() ## ## Creating a table ## ================ ## ## .. code-block:: Nim ## db.exec(sql"DROP TABLE IF EXISTS myTable") ## db.exec(sql("""CREATE TABLE myTable ( ## id integer, ## name varchar(50) not null)""")) ## ## Inserting data ## ============== ## ## .. code-block:: Nim ## db.exec(sql"INSERT INTO myTable (id, name) VALUES (0, ?)", ## "Jack") ## ## Larger example ## ============== ## ## .. code-block:: nim ## ## import db_sqlite, math ## ## let theDb = open("mytest.db", nil, nil, nil) ## ## theDb.exec(sql"Drop table if exists myTestTbl") ## theDb.exec(sql("""create table myTestTbl ( ## Id INTEGER PRIMARY KEY, ## Name VARCHAR(50) NOT NULL, ## i INT(11), ## f DECIMAL(18,10))""")) ## ## theDb.exec(sql"BEGIN") ## for i in 1..1000: ## theDb.exec(sql"INSERT INTO myTestTbl (name,i,f) VALUES (?,?,?)", ## "Item#" & $i, i, sqrt(i.float)) ## theDb.exec(sql"COMMIT") ## ## for x in theDb.fastRows(sql"select * from myTestTbl"): ## echo x ## ## let id = theDb.tryInsertId(sql"INSERT INTO myTestTbl (name,i,f) VALUES (?,?,?)", ## "Item#1001", 1001, sqrt(1001.0)) ## echo "Inserted item: ", theDb.getValue(sql"SELECT name FROM myTestTbl WHERE id=?", id) ## ## theDb.close() {.deadCodeElim: on.} # dce option deprecated import strutils, 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 nil. InstantRow* = Pstmt ## a handle that can be used to get a row's column ## text on demand {.deprecated: [TRow: Row, TDbConn: DbConn].} proc dbError*(db: DbConn) {.noreturn.} = ## raises a DbError exception. var e: ref DbError new(e) e.msg = $sqlite3.errmsg(db) raise e proc dbQuote*(s: string): string = ## DB quotes the string. if s.isNil: return "NULL" result = "'" for c in items(s): if c == '\'': add(result, "''") else: add(result, c) add(result, '\'') proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string = result = "" var a = 0 for c in items(string(formatstr)): if c == '?': add(result, dbQuote(args[a])) inc(a) else: add(result, c) proc tryExec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]): bool {. tags: [ReadDbEffect, WriteDbEffect].} = ## tries to execute the query and returns true if successful, false otherwise. 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:

discard """
  output: "1"
"""

proc viewInto(a: array[4, string]): lent string =
  result = a[0]

proc passToVar(x: var string) =
  discard

proc main =
  let x = ["1", "2", "3", "4"]
  echo viewInto(x)
  doAssert(not<