fixes #9728 - Nim - This repository contains the Nim compiler, Nim's stdlib, tools, and documentation. (mirror)

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author	Araq <rumpf_a@web.de>	2018-11-16 11:30:24 +0100
committer	Araq <rumpf_a@web.de>	2018-11-16 11:30:34 +0100
commit	4929f74023c55db6a1521b1e0647a99d94596e0e (patch)
tree	545862476c55b8c3ff10c4a19799cc58dbf6a528 /compiler/semparallel.nim
parent	4efbde84eeb0464d560a9451a5d60a746cc3e313 (diff)
download	Nim-4929f74023c55db6a1521b1e0647a99d94596e0e.tar.gz

fixes #9728

Diffstat (limited to 'compiler/semparallel.nim')

0 files changed, 0 insertions, 0 deletions

# # # Nimrod's Runtime Library # (c) Copyright 2012 Andreas Rumpf # # See the file "copying.txt", included in this # distribution, for details about the copyright. # ## A higher level `PostgreSQL`:idx: database wrapper. This interface ## is implemented for other databases too. import strutils, postgres type TDbConn* = PPGconn ## encapsulates a database connection TRow* = seq[string] ## a row of a dataset EDb* = object of EIO ## exception that is raised if a database error occurs TSqlQuery* = distinct string ## an SQL query string proc sql*(query: string): TSqlQuery {.noSideEffect, inline.} = ## constructs a TSqlQuery from the string `query`. This is supposed to be ## used as a raw-string-literal modifier: ## ``sql"update user set counter = counter + 1"`` ## ## If assertions are turned off, it does nothing. If assertions are turned ## on, later versions will check the string for valid syntax. result = TSqlQuery(query) proc dbError(db: TDbConn) {.noreturn.} = ## raises an EDb exception. var e: ref EDb new(e) e.msg = $PQerrorMessage(db) raise e proc dbError*(msg: string) {.noreturn.} = ## raises an EDb exception with message `msg`. var e: ref EDb new(e) e.msg = msg raise e proc dbQuote(s: string): string = result = "'" for c in items(s): if c == '\'': add(result, "''") else: add(result, c) add(result, '\'') proc dbFormat(formatstr: TSqlQuery, 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: TDbConn, query: TSqlQuery, args: varargs[string]): bool = ## tries to execute the query and returns true if successful, false otherwise. var q = dbFormat(query, args) var res = PQExec(db, q) result = PQresultStatus(res) == PGRES_COMMAND_OK PQclear(res) proc Exec*(db: TDbConn, query: TSqlQuery, args: varargs[string]) = ## executes the query and raises EDB if not successful. var q = dbFormat(query, args) var res = PQExec(db, q) if PQresultStatus(res) != PGRES_COMMAND_OK: dbError(db) PQclear(res) proc newRow(L: int): TRow = newSeq(result, L) for i in 0..L-1: result[i] = "" proc setupQuery(db: TDbConn, query: TSqlQuery, args: varargs[string]): PPGresult = var q = dbFormat(query, args) result = PQExec(db, q) if PQresultStatus(result) != PGRES_TUPLES_OK: dbError(db) proc setRow(res: PPGresult, r: var TRow, line, cols: int32) = for col in 0..cols-1: setLen(r[col], 0) var x = PQgetvalue(res, line, col) add(r[col], x) iterator FastRows*(db: TDbConn, query: TSqlQuery, args: varargs[string]): TRow = ## executes the query and iterates over the result dataset. This is very ## fast, but potenially dangerous: If the for-loop-body executes another ## query, the results can be undefined. For Postgres it is safe though. var res = setupQuery(db, query, args) var L = PQnfields(res) var result = newRow(L) for i in 0..PQntuples(res)-1: setRow(res, result, i, L) yield result PQclear(res) proc getRow*(db: TDbConn, query: TSqlQuery, args: varargs[string]): TRow = ## retrieves a single row. var res = setupQuery(db, query, args) var L = PQnfields(res) result = newRow(L) setRow(res, result, 0, L) PQclear(res) proc GetAllRows*(db: TDbConn, query: TSqlQuery, args: varargs[string]): seq[TRow] = ## executes the query and returns the whole result dataset. result = @[] for r in FastRows(db, query, args): result.add(r) iterator Rows*(db: TDbConn, query: TSqlQuery, args: varargs[string]): TRow = ## same as `FastRows`, but slower and safe. for r in items(GetAllRows(db, query, args)): yield r proc GetValue*(db: TDbConn, query: TSqlQuery, args: varargs[string]): string = ## executes the query and returns the result dataset's the first column ## of the first row. Returns "" if the dataset contains no rows. var x = PQgetvalue(setupQuery(db, query, args), 0, 0) result = if isNil(x): "" else: $x proc TryInsertID*(db: TDbConn, query: TSqlQuery, args: varargs[string]): int64 = ## executes the query (typically "INSERT") and returns the ## generated ID for the row or -1 in case of an error. For Postgre this adds ## ``RETURNING id`` to the query, so it only works if your primary key is ## named ``id``. var val = GetValue(db, TSqlQuery(string(query) & " RETURNING id"), args) if val.len > 0: result = ParseBiggestInt(val) else: result = -1 proc InsertID*(db: TDbConn, query: TSqlQuery, args: varargs[string]): int64 = ## executes the query (typically "INSERT") and returns the ## generated ID for the row. For Postgre this adds ## ``RETURNING id`` to the query, so it only works if your primary key is ## named ``id``. result = TryInsertID(db, query, args) if result < 0: dbError(db) proc ExecAffectedRows*(db: TDbConn, query: TSqlQuery, args: varargs[string]): int64 = ## executes the query (typically "UPDATE") and returns the ## number of affected rows. var q = dbFormat(query, args) var res = PQExec(db, q) if PQresultStatus(res) != PGRES_COMMAND_OK: dbError(db) result = parseBiggestInt($PQcmdTuples(res)) PQclear(res) proc Close*(db: TDbConn) = ## closes the database connection. if db != nil: PQfinish(db) proc Open*(connection, user, password, database: string): TDbConn = ## opens a database connection. Raises `EDb` if the connection could not ## be established. result = PQsetdbLogin(nil, nil, nil, nil, database, user, password) if PQStatus(result) != CONNECTION_OK: dbError(result) # result = nil


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