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| -rwxr-xr-x | lib/impure/db_mysql.nim | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/lib/impure/db_mysql.nim b/lib/impure/db_mysql.nim new file mode 100755 index 000000000..386da0cf7 --- /dev/null +++ b/lib/impure/db_mysql.nim @@ -0,0 +1,145 @@ +# Nimrod mySQL database wrapper +# (c) 2009 Andreas Rumpf + +import strutils, mysql + +type + TDbHandle* = PMySQL + TRow* = seq[string] + EDb* = object of EIO + +proc dbError(db: TDbHandle) {.noreturn.} = + ## raises an EDb exception. + var e: ref EDb + new(e) + e.msg = $mysql_error(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 + +when false: + proc dbQueryOpt*(db: TDbHandle, query: string, args: openarray[string]) = + var stmt = mysql_stmt_init(db) + if stmt == nil: dbError(db) + if mysql_stmt_prepare(stmt, query, len(query)) != 0: + dbError(db) + var + bind: seq[MYSQL_BIND] + discard mysql_stmt_close(stmt) + +proc dbQuote(s: string): string = + result = "'" + for c in items(s): + if c == '\'': add(result, "''") + else: add(result, c) + add(result, '\'') + +proc dbFormat(formatstr: string, args: openarray[string]): string = + result = "" + var a = 0 + for c in items(formatstr): + if c == '?': + add(result, dbQuote(args[a])) + inc(a) + else: + add(result, c) + +proc dbTryQuery*(db: TDbHandle, query: string, args: openarray[string]): bool = + var q = dbFormat(query, args) + return mysqlRealQuery(db, q, q.len) == 0'i32 + +proc dbQuery*(db: TDbHandle, query: string, args: openarray[string]) = + var q = dbFormat(query, args) + if mysqlRealQuery(db, q, q.len) != 0'i32: dbError(db) + +proc dbTryInsertID*(db: TDbHandle, query: string, + args: openarray[string]): int64 = + var q = dbFormat(query, args) + if mysqlRealQuery(db, q, q.len) != 0'i32: + result = -1'i64 + else: + result = mysql_insert_id(db) + +proc dbInsertID*(db: TDbHandle, query: string, args: openArray[string]): int64 = + result = dbTryInsertID(db, query, args) + if result < 0: dbError(db) + +proc dbQueryAffectedRows*(db: TDbHandle, query: string, + args: openArray[string]): int64 = + ## runs the query (typically "UPDATE") and returns the + ## number of affected rows + dbQuery(db, query, args) + result = mysql_affected_rows(db) + +proc newRow(L: int): TRow = + newSeq(result, L) + for i in 0..L-1: result[i] = "" + +proc properFreeResult(sqlres: PMYSQL_RES, row: cstringArray) = + if row != nil: + while mysqlFetchRow(sqlres) != nil: nil + mysqlFreeResult(sqlres) + +proc dbGetAllRows*(db: TDbHandle, query: string, + args: openarray[string]): seq[TRow] = + result = @[] + dbQuery(db, query, args) + var sqlres = mysqlUseResult(db) + if sqlres != nil: + var L = int(mysql_num_fields(sqlres)) + var row: cstringArray + var j = 0 + while true: + row = mysqlFetchRow(sqlres) + if row == nil: break + setLen(result, j+1) + newSeq(result[j], L) + for i in 0..L-1: result[j][i] = $row[i] + inc(j) + mysqlFreeResult(sqlres) + +iterator dbRows*(db: TDbHandle, query: string, + args: openarray[string]): TRow = + for r in items(dbGetAllRows(db, query, args)): yield r + +iterator dbFastRows*(db: TDbHandle, query: string, + args: openarray[string]): TRow = + # this is carefully optimized, so that the memory is reused! + dbQuery(db, query, args) + var sqlres = mysqlUseResult(db) + if sqlres != nil: + var L = int(mysql_num_fields(sqlres)) + var result = newRow(L) + var row: cstringArray + while true: + row = mysqlFetchRow(sqlres) + if row == nil: break + for i in 0..L-1: + setLen(result[i], 0) + add(result[i], row[i]) + yield result + properFreeResult(sqlres, row) + +proc dbGetValue*(db: TDbHandle, query: string, + args: openarray[string]): string = + result = "" + for row in dbFastRows(db, query, args): + result = row[0] + break + +proc dbClose*(db: TDbHandle) = + if db != nil: mysqlClose(db) + +proc dbOpen*(connection, user, password, database: string): TDbHandle = + result = mysqlInit(nil) + if result != nil: + if mysqlRealConnect(result, "", user, password, database, + 0'i32, nil, 0) == nil: + dbClose(result) + result = nil + |