big update for the db*.nim modules; uses new db_common.nim

lib/pure/db_common.nim

@@ -0,0 +1,96 @@
+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2015 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Common datatypes and definitions for all db_*.nim modules.
+
+type
+  DbError* = object of IOError ## exception that is raised if a database error occurs
+
+  SqlQuery* = distinct string ## an SQL query string
+
+
+  DbEffect* = object of IOEffect ## effect that denotes a database operation
+  ReadDbEffect* = object of DbEffect   ## effect that denotes a read operation
+  WriteDbEffect* = object of DbEffect  ## effect that denotes a write operation
+
+  DbTypeKind* = enum  ## a superset of datatypes that might be supported.
+    dbUnknown,        ## unknown datatype
+    dbSerial,         ## datatype used for primary auto-increment keys
+    dbNull,           ## datatype used for the NULL value
+    dbBit,            ## bit datatype
+    dbBool,           ## boolean datatype
+    dbBlob,           ## blob datatype
+    dbFixedChar,      ## string of fixed length
+    dbVarchar,        ## string datatype
+    dbJson,           ## JSON datatype
+    dbXml,            ## XML datatype
+    dbInt,            ## some integer type
+    dbUInt,           ## some unsigned integer type
+    dbDecimal,        ## decimal numbers (fixed-point number)
+    dbFloat,          ## some floating point type
+    dbDate,           ## a year-month-day description
+    dbTime,           ## HH:MM:SS information
+    dbDatetime,       ## year-month-day and HH:MM:SS information
+    dbTimestamp,      ## Timestamp values are stored as the number of seconds
+                      ## since the epoch ('1970-01-01 00:00:00' UTC).
+    dbTimeInterval,   ## an interval [a,b] of times
+    dbEnum,           ## some enum
+    dbSet,            ## set of enum values
+    dbArray,          ## an array of values
+    dbComposite,      ## composite type (record, struct, etc)
+    dbUrl,            ## a URL
+    dbUuid,           ## a UUID
+    dbInet,           ## an IP address
+    dbMacAddress,     ## a MAC address
+    dbPoint,          ## Point on a plane   (x,y)
+    dbLine,           ## Infinite line ((x1,y1),(x2,y2))
+    dbLseg,           ## Finite line segment   ((x1,y1),(x2,y2))
+    dbBox,            ## Rectangular box   ((x1,y1),(x2,y2))
+    dbPath,           ## Closed or open path (similar to polygon) ((x1,y1),...)
+    dbPolygon,        ## Polygon (similar to closed path)   ((x1,y1),...)
+    dbCircle,         ## Circle   <(x,y),r> (center point and radius)
+    dbUser1,          ## user definable datatype 1 (for unknown extensions)
+    dbUser2,          ## user definable datatype 2 (for unknown extensions)
+    dbUser3,          ## user definable datatype 3 (for unknown extensions)
+    dbUser4,          ## user definable datatype 4 (for unknown extensions)
+    dbUser5           ## user definable datatype 5 (for unknown extensions)
+
+  DbType* = object    ## describes a database type
+    kind*: DbTypeKind ## the kind of the described type
+    notNull*: bool    ## does the type contain NULL?
+    name*: string     ## the name of the type
+    size*: Natural    ## the size of the datatype; 0 if of variable size
+    precision*, scale*: Natural ## precision and scale of the number
+    min*, max*: BiggestInt ## the minimum and maximum of allowed values
+    validValues*: seq[string] ## valid values of an enum or a set
+
+  DbColumn* = object   ## information about a database column
+    name*: string      ## name of the column
+    tableName*: string ## name of the table the column belongs to (optional)
+    typ*: DbType       ## type of the column
+  DbColumns* = seq[DbColumn]
+
+{.deprecated: [EDb: DbError, TSqlQuery: SqlQuery, FDb: DbEffect,
+              FReadDb: ReadDbEffect, FWriteDb: WriteDbEffect].}
+
+template sql*(query: string): SqlQuery =
+  ## 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.
+  SqlQuery(query)
+
+proc dbError*(msg: string) {.noreturn, noinline.} =
+  ## raises an DbError exception with message `msg`.
+  var e: ref DbError
+  new(e)
+  e.msg = msg
+  raise e