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Merge branch 'devel' of https://github.com/nim-lang/Nim into devel

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Araq
2016-01-18 10:55:23 +01:00
committed by ringabout
parent e6e5e86f5c
commit a6664bf8e3
1 changed files with 64 additions and 47 deletions
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111
src/db_sqlite.nim
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@@ -1,7 +1,7 @@
#
#
# Nim's Runtime Library
# (c) Copyright 2012 Andreas Rumpf
# (c) Copyright 2015 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
@@ -40,47 +40,30 @@
##
## theDb.close()
{.deadCodeElim:on.}
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
## transformed always to the empty string.
## converted to nil.
InstantRow* = Pstmt ## a handle that can be used to get a row's column
## text on demand
EDb* = object of IOError ## exception that is raised if a database error occurs
{.deprecated: [TRow: Row, TDbConn: DbConn].}
SqlQuery* = distinct string ## an SQL query string
FDb* = object of IOEffect ## effect that denotes a database operation
FReadDb* = object of FDb ## effect that denotes a read operation
FWriteDb* = object of FDb ## effect that denotes a write operation
{.deprecated: [TRow: Row, TSqlQuery: SqlQuery, TDbConn: DbConn].}
proc sql*(query: string): SqlQuery {.noSideEffect, inline.} =
## constructs a SqlQuery 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 = SqlQuery(query)
proc dbError(db: DbConn) {.noreturn.} =
## raises an EDb exception.
var e: ref EDb
proc dbError*(db: DbConn) {.noreturn.} =
## raises a DbError exception.
var e: ref DbError
new(e)
e.msg = $sqlite3.errmsg(db)
raise e
proc dbError*(msg: string) {.noreturn.} =
## raises an EDb exception with message `msg`.
var e: ref EDb
new(e)
e.msg = msg
raise e
proc dbQuote(s: string): string =
proc dbQuote*(s: string): string =
## DB quotes the string.
if s.isNil: return "NULL"
result = "'"
for c in items(s):
@@ -99,7 +82,8 @@ proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string =
add(result, c)
proc tryExec*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): bool {.tags: [FReadDb, FWriteDb].} =
args: varargs[string, `$`]): bool {.
tags: [ReadDbEffect, WriteDbEffect].} =
## tries to execute the query and returns true if successful, false otherwise.
var q = dbFormat(query, args)
var stmt: sqlite3.Pstmt
@@ -108,8 +92,8 @@ proc tryExec*(db: DbConn, query: SqlQuery,
result = finalize(stmt) == SQLITE_OK
proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {.
tags: [FReadDb, FWriteDb].} =
## executes the query and raises EDB if not successful.
tags: [ReadDbEffect, WriteDbEffect].} =
## executes the query and raises DbError if not successful.
if not tryExec(db, query, args): dbError(db)
proc newRow(L: int): Row =
@@ -129,14 +113,14 @@ proc setRow(stmt: Pstmt, r: var Row, cols: cint) =
if not isNil(x): add(r[col], x)
iterator fastRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): Row {.tags: [FReadDb].} =
args: varargs[string, `$`]): 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.
##
## Breaking the fastRows() iterator during a loop will cause the next
## database query to raise an [EDb] exception ``unable to close due to ...``.
## database query to raise a DbError exception ``unable to close due to ...``.
var stmt = setupQuery(db, query, args)
var L = (column_count(stmt))
var result = newRow(L)
@@ -147,14 +131,47 @@ iterator fastRows*(db: DbConn, query: SqlQuery,
iterator instantRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): InstantRow
{.tags: [FReadDb].} =
{.tags: [ReadDbEffect].} =
## same as fastRows but returns a handle that can be used to get column text
## on demand using []. Returned handle is valid only within the interator body.
## on demand using []. Returned handle is valid only within the iterator body.
var stmt = setupQuery(db, query, args)
while step(stmt) == SQLITE_ROW:
yield stmt
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].} =
## same as fastRows but returns a handle that can be used to get column text
## on demand using []. Returned handle is valid only within the iterator body.
var stmt = setupQuery(db, query, args)
setColumns(columns, stmt)
while step(stmt) == SQLITE_ROW:
yield stmt
if finalize(stmt) != SQLITE_OK: dbError(db)
proc `[]`*(row: InstantRow, col: int32): string {.inline.} =
## returns text for given column of the row
$column_text(row, col)
@@ -164,7 +181,7 @@ proc len*(row: InstantRow): int32 {.inline.} =
column_count(row)
proc getRow*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): Row {.tags: [FReadDb].} =
args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
## retrieves a single row. If the query doesn't return any rows, this proc
## will return a Row with empty strings for each column.
var stmt = setupQuery(db, query, args)
@@ -175,19 +192,19 @@ proc getRow*(db: DbConn, query: SqlQuery,
if finalize(stmt) != SQLITE_OK: dbError(db)
proc getAllRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): seq[Row] {.tags: [FReadDb].} =
args: varargs[string, `$`]): seq[Row] {.tags: [ReadDbEffect].} =
## executes the query and returns the whole result dataset.
result = @[]
for r in fastRows(db, query, args):
result.add(r)
iterator rows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): Row {.tags: [FReadDb].} =
args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
## same as `FastRows`, but slower and safe.
for r in fastRows(db, query, args): yield r
proc getValue*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): string {.tags: [FReadDb].} =
args: varargs[string, `$`]): string {.tags: [ReadDbEffect].} =
## executes the query and returns the first column of the first row of the
## result dataset. Returns "" if the dataset contains no rows or the database
## value is NULL.
@@ -205,7 +222,7 @@ proc getValue*(db: DbConn, query: SqlQuery,
proc tryInsertID*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): int64
{.tags: [FWriteDb], raises: [].} =
{.tags: [WriteDbEffect], raises: [].} =
## executes the query (typically "INSERT") and returns the
## generated ID for the row or -1 in case of an error.
var q = dbFormat(query, args)
@@ -218,7 +235,7 @@ proc tryInsertID*(db: DbConn, query: SqlQuery,
result = -1
proc insertID*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): int64 {.tags: [FWriteDb].} =
args: varargs[string, `$`]): int64 {.tags: [WriteDbEffect].} =
## 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
@@ -228,18 +245,18 @@ proc insertID*(db: DbConn, query: SqlQuery,
proc execAffectedRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): int64 {.
tags: [FReadDb, FWriteDb].} =
tags: [ReadDbEffect, WriteDbEffect].} =
## executes the query (typically "UPDATE") and returns the
## number of affected rows.
exec(db, query, args)
result = changes(db)
proc close*(db: DbConn) {.tags: [FDb].} =
proc close*(db: DbConn) {.tags: [DbEffect].} =
## closes the database connection.
if sqlite3.close(db) != SQLITE_OK: dbError(db)
proc open*(connection, user, password, database: string): DbConn {.
tags: [FDb].} =
tags: [DbEffect].} =
## opens a database connection. Raises `EDb` if the connection could not
## be established. Only the ``connection`` parameter is used for ``sqlite``.
var db: DbConn
@@ -249,7 +266,7 @@ proc open*(connection, user, password, database: string): DbConn {.
dbError(db)
proc setEncoding*(connection: DbConn, encoding: string): bool {.
tags: [FDb].} =
tags: [DbEffect].} =
## sets the encoding of a database connection, returns true for
## success, false for failure.
##