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lib/impure - Dropped 'T' from types

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pdw 2015-05-24 22:24:07 -05:00 • committed by Araq
commit ea03fc6886
7 changed files with 165 additions and 157 deletions
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88
lib/impure/db_postgres.nim
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@ -13,28 +13,30 @@
import strutils, postgres
type
TDbConn* = PPGconn ## encapsulates a database connection
TRow* = seq[string] ## a row of a dataset. NULL database values will be
DbConn* = PPGconn ## encapsulates a database connection
Row* = seq[string] ## a row of a dataset. NULL database values will be
## transformed always to the empty string.
EDb* = object of IOError ## exception that is raised if a database error occurs
TSqlQuery* = distinct string ## an SQL query string
TSqlPrepared* = distinct string ## a identifier for the prepared queries
SqlQuery* = distinct string ## an SQL query string
SqlPrepared* = distinct string ## a identifier for the prepared queries
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,
TSqlPrepared: SqlPrepared].}
proc sql*(query: string): TSqlQuery {.noSideEffect, inline.} =
## constructs a TSqlQuery from the string `query`. This is supposed to be
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 = TSqlQuery(query)
result = SqlQuery(query)
proc dbError*(db: TDbConn) {.noreturn.} =
proc dbError*(db: DbConn) {.noreturn.} =
## raises an EDb exception.
var e: ref EDb
new(e)
@ -56,7 +58,7 @@ proc dbQuote*(s: string): string =
else: add(result, c)
add(result, '\'')
proc dbFormat(formatstr: TSqlQuery, args: varargs[string]): string =
proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string =
result = ""
var a = 0
for c in items(string(formatstr)):
@ -69,7 +71,7 @@ proc dbFormat(formatstr: TSqlQuery, args: varargs[string]): string =
else:
add(result, c)
proc tryExec*(db: TDbConn, query: TSqlQuery,
proc tryExec*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): bool {.tags: [FReadDB, FWriteDb].} =
## tries to execute the query and returns true if successful, false otherwise.
var arr = allocCStringArray(args)
@ -79,7 +81,7 @@ proc tryExec*(db: TDbConn, query: TSqlQuery,
result = pqresultStatus(res) == PGRES_COMMAND_OK
pqclear(res)
proc exec*(db: TDbConn, query: TSqlQuery, args: varargs[string, `$`]) {.
proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {.
tags: [FReadDB, FWriteDb].} =
## executes the query and raises EDB if not successful.
var arr = allocCStringArray(args)
@ -89,7 +91,7 @@ proc exec*(db: TDbConn, query: TSqlQuery, args: varargs[string, `$`]) {.
if pqresultStatus(res) != PGRES_COMMAND_OK: dbError(db)
pqclear(res)
proc exec*(db: TDbConn, stmtName: TSqlPrepared,
proc exec*(db: DbConn, stmtName: SqlPrepared,
args: varargs[string]) {.tags: [FReadDB, FWriteDb].} =
var arr = allocCStringArray(args)
var res = pqexecPrepared(db, stmtName.string, int32(args.len), arr,
@ -98,11 +100,11 @@ proc exec*(db: TDbConn, stmtName: TSqlPrepared,
if pqResultStatus(res) != PGRES_COMMAND_OK: dbError(db)
pqclear(res)
proc newRow(L: int): TRow =
proc newRow(L: int): Row =
newSeq(result, L)
for i in 0..L-1: result[i] = ""
proc setupQuery(db: TDbConn, query: TSqlQuery,
proc setupQuery(db: DbConn, query: SqlQuery,
args: varargs[string]): PPGresult =
var arr = allocCStringArray(args)
result = pqexecParams(db, query.string, int32(args.len), nil, arr,
@ -110,7 +112,7 @@ proc setupQuery(db: TDbConn, query: TSqlQuery,
deallocCStringArray(arr)
if pqResultStatus(result) != PGRES_TUPLES_OK: dbError(db)
proc setupQuery(db: TDbConn, stmtName: TSqlPrepared,
proc setupQuery(db: DbConn, stmtName: SqlPrepared,
args: varargs[string]): PPGresult =
var arr = allocCStringArray(args)
result = pqexecPrepared(db, stmtName.string, int32(args.len), arr,
@ -118,13 +120,13 @@ proc setupQuery(db: TDbConn, stmtName: TSqlPrepared,
deallocCStringArray(arr)
if pqResultStatus(result) != PGRES_TUPLES_OK: dbError(db)
proc prepare*(db: TDbConn; stmtName: string, query: TSqlQuery;
nParams: int): TSqlPrepared =
proc prepare*(db: DbConn; stmtName: string, query: SqlQuery;
nParams: int): SqlPrepared =
var res = pqprepare(db, stmtName, query.string, int32(nParams), nil)
if pqResultStatus(res) != PGRES_COMMAND_OK: dbError(db)
return TSqlPrepared(stmtName)
return SqlPrepared(stmtName)
proc setRow(res: PPGresult, r: var TRow, line, cols: int32) =
proc setRow(res: PPGresult, r: var Row, line, cols: int32) =
for col in 0..cols-1:
setLen(r[col], 0)
let x = pqgetvalue(res, line, col)
@ -133,8 +135,8 @@ proc setRow(res: PPGresult, r: var TRow, line, cols: int32) =
else:
add(r[col], x)
iterator fastRows*(db: TDbConn, query: TSqlQuery,
args: varargs[string, `$`]): TRow {.tags: [FReadDB].} =
iterator fastRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
## 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.
@ -146,8 +148,8 @@ iterator fastRows*(db: TDbConn, query: TSqlQuery,
yield result
pqclear(res)
iterator fastRows*(db: TDbConn, stmtName: TSqlPrepared,
args: varargs[string, `$`]): TRow {.tags: [FReadDB].} =
iterator fastRows*(db: DbConn, stmtName: SqlPrepared,
args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
## executes the prepared query and iterates over the result dataset.
var res = setupQuery(db, stmtName, args)
var L = pqNfields(res)
@ -157,44 +159,44 @@ iterator fastRows*(db: TDbConn, stmtName: TSqlPrepared,
yield result
pqClear(res)
proc getRow*(db: TDbConn, query: TSqlQuery,
args: varargs[string, `$`]): TRow {.tags: [FReadDB].} =
proc getRow*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
## retrieves a single row. If the query doesn't return any rows, this proc
## will return a TRow with empty strings for each column.
## will return a Row with empty strings for each column.
var res = setupQuery(db, query, args)
var L = pqnfields(res)
result = newRow(L)
setRow(res, result, 0, L)
pqclear(res)
proc getRow*(db: TDbConn, stmtName: TSqlPrepared,
args: varargs[string, `$`]): TRow {.tags: [FReadDB].} =
proc getRow*(db: DbConn, stmtName: SqlPrepared,
args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
var res = setupQuery(db, stmtName, args)
var L = pqNfields(res)
result = newRow(L)
setRow(res, result, 0, L)
pqClear(res)
proc getAllRows*(db: TDbConn, query: TSqlQuery,
args: varargs[string, `$`]): seq[TRow] {.tags: [FReadDB].} =
proc getAllRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): seq[Row] {.tags: [FReadDB].} =
## executes the query and returns the whole result dataset.
result = @[]
for r in fastRows(db, query, args):
result.add(r)
proc getAllRows*(db: TDbConn, stmtName: TSqlPrepared,
args: varargs[string, `$`]): seq[TRow] {.tags: [FReadDB].} =
proc getAllRows*(db: DbConn, stmtName: SqlPrepared,
args: varargs[string, `$`]): seq[Row] {.tags: [FReadDB].} =
## executes the prepared query and returns the whole result dataset.
result = @[]
for r in fastRows(db, stmtName, args):
result.add(r)
iterator rows*(db: TDbConn, query: TSqlQuery,
args: varargs[string, `$`]): TRow {.tags: [FReadDB].} =
iterator rows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): Row {.tags: [FReadDB].} =
## same as `fastRows`, but slower and safe.
for r in items(getAllRows(db, query, args)): yield r
proc getValue*(db: TDbConn, query: TSqlQuery,
proc getValue*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): string {.tags: [FReadDB].} =
## 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
@ -202,20 +204,20 @@ proc getValue*(db: TDbConn, query: TSqlQuery,
var x = pqgetvalue(setupQuery(db, query, args), 0, 0)
result = if isNil(x): "" else: $x
proc tryInsertID*(db: TDbConn, query: TSqlQuery,
proc tryInsertID*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): int64 {.tags: [FWriteDb].}=
## 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 x = pqgetvalue(setupQuery(db, TSqlQuery(string(query) & " RETURNING id"),
var x = pqgetvalue(setupQuery(db, SqlQuery(string(query) & " RETURNING id"),
args), 0, 0)
if not isNil(x):
result = parseBiggestInt($x)
else:
result = -1
proc insertID*(db: TDbConn, query: TSqlQuery,
proc insertID*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): int64 {.tags: [FWriteDb].} =
## executes the query (typically "INSERT") and returns the
## generated ID for the row. For Postgre this adds
@ -224,7 +226,7 @@ proc insertID*(db: TDbConn, query: TSqlQuery,
result = tryInsertID(db, query, args)
if result < 0: dbError(db)
proc execAffectedRows*(db: TDbConn, query: TSqlQuery,
proc execAffectedRows*(db: DbConn, query: SqlQuery,
args: varargs[string, `$`]): int64 {.tags: [
FReadDB, FWriteDb].} =
## executes the query (typically "UPDATE") and returns the
@ -235,11 +237,11 @@ proc execAffectedRows*(db: TDbConn, query: TSqlQuery,
result = parseBiggestInt($pqcmdTuples(res))
pqclear(res)
proc close*(db: TDbConn) {.tags: [FDb].} =
proc close*(db: DbConn) {.tags: [FDb].} =
## closes the database connection.
if db != nil: pqfinish(db)
proc open*(connection, user, password, database: string): TDbConn {.
proc open*(connection, user, password, database: string): DbConn {.
tags: [FDb].} =
## opens a database connection. Raises `EDb` if the connection could not
## be established.
@ -261,8 +263,8 @@ proc open*(connection, user, password, database: string): TDbConn {.
result = pqsetdbLogin(nil, nil, nil, nil, database, user, password)
if pqStatus(result) != CONNECTION_OK: dbError(result) # result = nil
proc setEncoding*(connection: TDbConn, encoding: string): bool {.
proc setEncoding*(connection: DbConn, encoding: string): bool {.
tags: [FDb].} =
## sets the encoding of a database connection, returns true for
## success, false for failure.
return pqsetClientEncoding(connection, encoding) == 0
return pqsetClientEncoding(connection, encoding) == 0