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Diffstat (limited to 'lib/impure/db_postgres.nim')
| -rw-r--r-- | lib/impure/db_postgres.nim | 366 |
1 files changed, 0 insertions, 366 deletions
diff --git a/lib/impure/db_postgres.nim b/lib/impure/db_postgres.nim deleted file mode 100644 index 9bdbae4c2..000000000 --- a/lib/impure/db_postgres.nim +++ /dev/null @@ -1,366 +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 `PostgreSQL`:idx: database wrapper. This interface -## is implemented for other databases also. -## -## 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 (?, ?, ?)" -## -## **Note**: There are two approaches to parameter substitution support by -## this module. -## -## 1. ``SqlQuery`` using ``?, ?, ?, ...`` (same as all the ``db_*`` modules) -## -## 2. ``SqlPrepared`` using ``$1, $2, $3, ...`` -## -## .. code-block:: Nim -## prepare(db, "myExampleInsert", -## sql"""INSERT INTO myTable -## (colA, colB, colC) -## VALUES ($1, $2, $3)""", -## 3) -## -## Examples -## -------- -## -## Opening a connection to a database -## ================================== -## -## .. code-block:: Nim -## import db_postgres -## 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, ?)", -## "Dominik") -import strutils, postgres - -import db_common -export db_common - -type - DbConn* = PPGconn ## encapsulates a database connection - Row* = seq[string] ## a row of a dataset. NULL database values will be - ## converted to nil. - InstantRow* = tuple[res: PPGresult, line: int32] ## a handle that can be - ## used to get a row's - ## column text on demand - SqlPrepared* = distinct string ## a identifier for the prepared queries - -{.deprecated: [TRow: Row, TDbConn: DbConn, - TSqlPrepared: SqlPrepared].} - -proc dbError*(db: DbConn) {.noreturn.} = - ## raises a DbError exception. - var e: ref DbError - new(e) - e.msg = $pqErrorMessage(db) - raise e - -proc dbQuote*(s: string): string = - ## DB quotes the string. - result = "'" - for c in items(s): - if c == '\'': add(result, "''") - else: add(result, c) - add(result, '\'') - -proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string = - result = "" - var a = 0 - if args.len > 0 and not string(formatstr).contains("?"): - dbError("""parameter substitution expects "?" """) - for c in items(string(formatstr)): - if c == '?': - if args[a] == nil: - add(result, "NULL") - else: - add(result, dbQuote(args[a])) - inc(a) - else: - add(result, c) - -proc tryExec*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): bool {.tags: [ReadDbEffect, WriteDbEffect].} = - ## tries to execute the query and returns true if successful, false otherwise. - var res = pqexecParams(db, dbFormat(query, args), 0, nil, nil, - nil, nil, 0) - result = pqresultStatus(res) == PGRES_COMMAND_OK - pqclear(res) - -proc tryExec*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string, `$`]): bool {.tags: [ - ReadDbEffect, WriteDbEffect].} = - ## tries to execute the query and returns true if successful, false otherwise. - var arr = allocCStringArray(args) - var res = pqexecPrepared(db, stmtName.string, int32(args.len), arr, - nil, nil, 0) - deallocCStringArray(arr) - result = pqresultStatus(res) == PGRES_COMMAND_OK - pqclear(res) - -proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {. - tags: [ReadDbEffect, WriteDbEffect].} = - ## executes the query and raises EDB if not successful. - var res = pqexecParams(db, dbFormat(query, args), 0, nil, nil, - nil, nil, 0) - if pqresultStatus(res) != PGRES_COMMAND_OK: dbError(db) - pqclear(res) - -proc exec*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string]) {.tags: [ReadDbEffect, WriteDbEffect].} = - var arr = allocCStringArray(args) - var res = pqexecPrepared(db, stmtName.string, int32(args.len), arr, - nil, nil, 0) - deallocCStringArray(arr) - if pqResultStatus(res) != PGRES_COMMAND_OK: dbError(db) - pqclear(res) - -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]): PPGresult = - result = pqexec(db, dbFormat(query, args)) - if pqResultStatus(result) != PGRES_TUPLES_OK: dbError(db) - -proc setupQuery(db: DbConn, stmtName: SqlPrepared, - args: varargs[string]): PPGresult = - var arr = allocCStringArray(args) - result = pqexecPrepared(db, stmtName.string, int32(args.len), arr, - nil, nil, 0) - deallocCStringArray(arr) - if pqResultStatus(result) != PGRES_TUPLES_OK: dbError(db) - -proc prepare*(db: DbConn; stmtName: string, query: SqlQuery; - nParams: int): SqlPrepared = - if nParams > 0 and not string(query).contains("$1"): - dbError("""parameter substitution expects "$1" """) - var res = pqprepare(db, stmtName, query.string, int32(nParams), nil) - if pqResultStatus(res) != PGRES_COMMAND_OK: dbError(db) - return SqlPrepared(stmtName) - -proc setRow(res: PPGresult, r: var Row, line, cols: int32) = - for col in 0..cols-1: - setLen(r[col], 0) - let x = pqgetvalue(res, line, col) - if x.isNil: - r[col] = nil - else: - add(r[col], x) - -iterator fastRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## executes the query and iterates over the result dataset. This is very - ## fast, but 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) - -iterator fastRows*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## executes the prepared query and iterates over the result dataset. - var res = setupQuery(db, stmtName, args) - var L = pqNfields(res) - var result = newRow(L) - for i in 0..pqNtuples(res)-1: - setRow(res, result, i, L) - yield result - pqClear(res) - -iterator instantRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): 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 iterator body. - var res = setupQuery(db, query, args) - for i in 0..pqNtuples(res)-1: - yield (res: res, line: i) - pqClear(res) - -iterator instantRows*(db: DbConn, stmtName: SqlPrepared, - 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 iterator body. - var res = setupQuery(db, stmtName, args) - for i in 0..pqNtuples(res)-1: - yield (res: res, line: i) - pqClear(res) - -proc `[]`*(row: InstantRow, col: int32): string {.inline.} = - ## returns text for given column of the row - $pqgetvalue(row.res, row.line, col) - -proc len*(row: InstantRow): int32 {.inline.} = - ## returns number of columns in the row - pqNfields(row.res) - -proc getRow*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): 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. - var res = setupQuery(db, query, args) - var L = pqnfields(res) - result = newRow(L) - setRow(res, result, 0, L) - pqclear(res) - -proc getRow*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - var res = setupQuery(db, stmtName, args) - var L = pqNfields(res) - result = newRow(L) - setRow(res, result, 0, L) - pqClear(res) - -proc getAllRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): seq[Row] {. - tags: [ReadDbEffect].} = - ## executes the query and returns the whole result dataset. - result = @[] - for r in fastRows(db, query, args): - result.add(r) - -proc getAllRows*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string, `$`]): seq[Row] {.tags: - [ReadDbEffect].} = - ## executes the prepared query and returns the whole result dataset. - result = @[] - for r in fastRows(db, stmtName, args): - result.add(r) - -iterator rows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## same as `fastRows`, but slower and safe. - for r in items(getAllRows(db, query, args)): yield r - -iterator rows*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = - ## same as `fastRows`, but slower and safe. - for r in items(getAllRows(db, stmtName, args)): yield r - -proc getValue*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): 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. - var x = pqgetvalue(setupQuery(db, query, args), 0, 0) - result = if isNil(x): "" else: $x - -proc tryInsertID*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {. - tags: [WriteDbEffect].}= - ## 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, SqlQuery(string(query) & " RETURNING id"), - args), 0, 0) - if not isNil(x): - result = parseBiggestInt($x) - else: - result = -1 - -proc insertID*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {. - tags: [WriteDbEffect].} = - ## executes the query (typically "INSERT") and returns the - ## generated ID for the row. 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: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {.tags: [ - ReadDbEffect, WriteDbEffect].} = - ## executes the query (typically "UPDATE") and returns the - ## number of affected rows. - var q = dbFormat(query, args) - var res = pqExec(db, q) - if pqresultStatus(res) != PGRES_COMMAND_OK: dbError(db) - result = parseBiggestInt($pqcmdTuples(res)) - pqclear(res) - -proc execAffectedRows*(db: DbConn, stmtName: SqlPrepared, - args: varargs[string, `$`]): int64 {.tags: [ - ReadDbEffect, WriteDbEffect].} = - ## executes the query (typically "UPDATE") and returns the - ## number of affected rows. - var arr = allocCStringArray(args) - var res = pqexecPrepared(db, stmtName.string, int32(args.len), arr, - nil, nil, 0) - deallocCStringArray(arr) - if pqresultStatus(res) != PGRES_COMMAND_OK: dbError(db) - result = parseBiggestInt($pqcmdTuples(res)) - pqclear(res) - -proc close*(db: DbConn) {.tags: [DbEffect].} = - ## closes the database connection. - if db != nil: pqfinish(db) - -proc open*(connection, user, password, database: string): DbConn {. - tags: [DbEffect].} = - ## opens a database connection. Raises `EDb` if the connection could not - ## be established. - ## - ## Clients can also use Postgres keyword/value connection strings to - ## connect. - ## - ## Example: - ## - ## .. code-block:: nim - ## - ## con = open("", "", "", "host=localhost port=5432 dbname=mydb") - ## - ## See http://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING - ## for more information. - ## - ## Note that the connection parameter is not used but exists to maintain - ## the nim db api. - result = pqsetdbLogin(nil, nil, nil, nil, database, user, password) - if pqStatus(result) != CONNECTION_OK: dbError(result) # result = nil - -proc setEncoding*(connection: DbConn, encoding: string): bool {. - tags: [DbEffect].} = - ## sets the encoding of a database connection, returns true for - ## success, false for failure. - return pqsetClientEncoding(connection, encoding) == 0 - - -# Tests are in ../../tests/untestable/tpostgres. |