transition odbcDataType() to S4 (#756)

Author: simonpcouch

DESCRIPTION

@@ -49,6 +49,7 @@ RoxygenNote: 7.3.0
 SystemRequirements: GNU make, An ODBC3 driver manager and drivers.
 Collate: 
     'RcppExports.R'
+    'aaa-odbc-data-type.R'
     'connection-pane.R'
     'dbi-connection.R'
     'odbc-connection.R'
@@ -76,7 +77,6 @@ Collate:
     'driver-vertica.R'
     'odbc-config.R'
     'odbc-data-sources.R'
-    'odbc-data-type.R'
     'odbc-drivers.R'
     'odbc-package.R'
     'odbc.R'

NAMESPACE

@@ -1,20 +1,5 @@
 # Generated by roxygen2: do not edit by hand
 
-S3method(odbcDataType,"Microsoft SQL Server")
-S3method(odbcDataType,"Spark SQL")
-S3method(odbcDataType,"Vertica Database")
-S3method(odbcDataType,ACCESS)
-S3method(odbcDataType,BigQuery)
-S3method(odbcDataType,Hive)
-S3method(odbcDataType,Impala)
-S3method(odbcDataType,MySQL)
-S3method(odbcDataType,Oracle)
-S3method(odbcDataType,PostgreSQL)
-S3method(odbcDataType,Redshift)
-S3method(odbcDataType,SQLite)
-S3method(odbcDataType,Snowflake)
-S3method(odbcDataType,Teradata)
-S3method(odbcDataType,default)
 S3method(odbcListColumns,OdbcConnection)
 S3method(odbcListObjectTypes,default)
 S3method(odbcListObjects,OdbcConnection)
@@ -38,13 +23,22 @@ export(quote_value)
 exportClasses("DB2/AIX64")
 exportClasses("Microsoft SQL Server")
 exportClasses("Spark SQL")
+exportClasses("Vertica Database")
+exportClasses(ACCESS)
+exportClasses(BigQuery)
 exportClasses(DatabricksOdbcDriver)
 exportClasses(HDB)
 exportClasses(Hive)
+exportClasses(Impala)
+exportClasses(MySQL)
 exportClasses(OdbcConnection)
 exportClasses(OdbcDriver)
 exportClasses(OdbcResult)
 exportClasses(Oracle)
+exportClasses(PostgreSQL)
+exportClasses(Redshift)
+exportClasses(SQLite)
+exportClasses(Snowflake)
 exportClasses(Teradata)
 exportMethods(dbAppendTable)
 exportMethods(dbBegin)
@@ -74,6 +68,7 @@ exportMethods(dbRollback)
 exportMethods(dbSendQuery)
 exportMethods(dbSendStatement)
 exportMethods(dbWriteTable)
+exportMethods(odbcDataType)
 exportMethods(show)
 exportMethods(sqlCreateTable)
 exportMethods(sqlData)

NEWS.md

@@ -1,7 +1,11 @@
 # odbc (development version)
 
+* Transitioned `odbcDataType()` to use S4 for consistency. S3 methods defined
+  locally will need to be rewritten (#701).
+
 * Teradata: Resolved issue when previewing tables using the Connections pane.
 
+
 # odbc 1.4.2
 
 * `dbAppendTable()` Improve performance by checking existence once (#691).

R/odbc-data-type.R R/aaa-odbc-data-type.R

@@ -1,7 +1,10 @@
 #' Return the corresponding ODBC data type for an R object
 #'
+#' @description
+#'
 #' This is used when creating a new table with `dbWriteTable()`.
-#' Databases with default methods defined are
+#' Databases with default methods defined are:
+#'
 #' - MySQL
 #' - PostgreSQL
 #' - SQL Server
@@ -15,61 +18,51 @@
 #' - BigQuery
 #' - Teradata
 #' - Access
+#' - Snowflake
+#'
+#' @details
 #'
 #' If you are using a different database and `dbWriteTable()` fails with a SQL
 #' parsing error the default method is not appropriate, you will need to write
-#' a new method.
-#'
-#' @section Defining a new dbDataType method:
-#'
-#' The object type for your connection will be the database name retrieved by
-#' `dbGetInfo(con)$dbms.name`. Use the documentation provided with your
-#' database to determine appropriate values for each R data type. An example
-#' method definition of a fictional `foo` database follows.
-#' ```
-#' con <- dbConnect(odbc::odbc(), "FooConnection")
-#' dbGetInfo(con)$dbms.name
-#' #> [1] "foo"
+#' a new method. The object type for your method will be the database name
+#' retrieved by `dbGetInfo(con)$dbms.name`. Use the documentation provided with
+#' your database to determine appropriate values for each R data type.
 #'
-#' `odbcDataType.foo <- function(con, obj, ...) {
-#'   switch_type(obj,
-#'     factor = "VARCHAR(255)",
-#'     datetime = "TIMESTAMP",
-#'     date = "DATE",
-#'     binary = "BINARY",
-#'     integer = "INTEGER",
-#'     double = "DOUBLE",
-#'     character = "VARCHAR(255)",
-#'     logical = "BIT",
-#'     list = "VARCHAR(255)",
-#'     stop("Unsupported type", call. = FALSE)
-#'   )
-#' }
-#' ```
 #' @param con A driver connection object, as returned by `dbConnect()`.
 #' @param obj An R object.
 #' @param ... Additional arguments passed to methods.
 #' @return Corresponding SQL type for the `obj`.
 #' @export
-odbcDataType <- function(con, obj, ...) UseMethod("odbcDataType")
+setGeneric(
+  "odbcDataType",
+  valueClass = "character",
+  function(con, obj, ...) {
+    standardGeneric("odbcDataType")
+  }
+)
 
 #' @export
-odbcDataType.default <- function(con, obj, ...) {
-  switch_type(obj,
-    factor = "VARCHAR(255)",
-    datetime = "TIMESTAMP",
-    date = "DATE",
-    time = "TIME",
-    binary = "VARBINARY(255)",
-    integer = "INTEGER",
-    int64 = "INTEGER",
-    double = "DOUBLE PRECISION",
-    character = "VARCHAR(255)",
-    logical = "BIT", # only valid if DB supports Null fields
-    list = "VARCHAR(255)",
-    stop("Unsupported type", call. = FALSE)
-  )
-}
+#' @rdname odbcDataType
+#' @usage NULL
+setMethod("odbcDataType", "ANY",
+  function(con, obj, ...) {
+    switch_type(
+      obj,
+      factor = "VARCHAR(255)",
+      datetime = "TIMESTAMP",
+      date = "DATE",
+      time = "TIME",
+      binary = "VARBINARY(255)",
+      integer = "INTEGER",
+      int64 = "INTEGER",
+      double = "DOUBLE PRECISION",
+      character = "VARCHAR(255)",
+      logical = "BIT", # only valid if DB supports Null fields
+      list = "VARCHAR(255)",
+      stop("Unsupported type", call. = FALSE)
+    )
+  }
+)
 
 switch_type <- function(obj, ...) {
   switch(object_type(obj),

R/driver-access.R

@@ -2,20 +2,28 @@
 NULL
 
 #' @export
-`odbcDataType.ACCESS` <- function(con, obj, ...) {
-  switch_type(
-    obj,
-    factor = varchar(obj),
-    datetime = "DATETIME",
-    date = "DATE",
-    time = "TIME",
-    binary = "BINARY",
-    integer = "INTEGER",
-    int64 = "INTEGER",
-    double = "DOUBLE",
-    character = varchar(obj),
-    logical = "BIT",
-    list = varchar(obj),
-    stop("Unsupported type", call. = FALSE)
-  )
-}
+#' @rdname DBI-classes
+setClass("ACCESS", contains = "OdbcConnection")
+
+#' @export
+#' @rdname odbcDataType
+#' @usage NULL
+setMethod("odbcDataType", "ACCESS",
+  function(con, obj, ...) {
+    switch_type(
+      obj,
+      factor = varchar(obj),
+      datetime = "DATETIME",
+      date = "DATE",
+      time = "TIME",
+      binary = "BINARY",
+      integer = "INTEGER",
+      int64 = "INTEGER",
+      double = "DOUBLE",
+      character = varchar(obj),
+      logical = "BIT",
+      list = varchar(obj),
+      stop("Unsupported type", call. = FALSE)
+    )
+  }
+)

R/driver-bigquery.R

@@ -2,18 +2,27 @@
 NULL
 
 #' @export
-`odbcDataType.BigQuery` <- function(con, obj, ...) {
-  switch_type(obj,
-    factor = "STRING",
-    datetime = "TIMESTAMP",
-    time = "TIME",
-    date = "DATE",
-    binary = "BYTES",
-    integer = "INT64",
-    int64 = "INT64",
-    double = "FLOAT64",
-    character = "STRING",
-    logical = "BOOL",
-    stop("Unsupported type", call. = FALSE)
-  )
-}
+#' @rdname DBI-classes
+setClass("BigQuery", contains = "OdbcConnection")
+
+#' @export
+#' @rdname odbcDataType
+#' @usage NULL
+setMethod("odbcDataType", "BigQuery",
+  function(con, obj, ...) {
+    switch_type(
+      obj,
+      factor = "STRING",
+      datetime = "TIMESTAMP",
+      time = "TIME",
+      date = "DATE",
+      binary = "BYTES",
+      integer = "INT64",
+      int64 = "INT64",
+      double = "FLOAT64",
+      character = "STRING",
+      logical = "BOOL",
+      stop("Unsupported type", call. = FALSE)
+    )
+  }
+)

R/driver-hive.R

@@ -23,19 +23,24 @@ setMethod("dbQuoteString", c("Hive", "character"),
 
 
 #' @export
-`odbcDataType.Hive` <- function(con, obj, ...) {
-  switch_type(obj,
-    factor = "STRING",
-    datetime = "TIMESTAMP",
-    date = "DATE",
-    binary = "BINARY",
-    integer = "INT",
-    int64 = "INT",
-    double = "DOUBLE",
-    character = "STRING",
-    logical = "BOOLEAN",
-    list = "STRING",
-    time = ,
-    stop("Unsupported type", call. = FALSE)
-  )
-}
+#' @rdname odbcDataType
+#' @usage NULL
+setMethod("odbcDataType", "Hive",
+  function(con, obj, ...) {
+    switch_type(
+      obj,
+      factor = "STRING",
+      datetime = "TIMESTAMP",
+      date = "DATE",
+      binary = "BINARY",
+      integer = "INT",
+      int64 = "INT",
+      double = "DOUBLE",
+      character = "STRING",
+      logical = "BOOLEAN",
+      list = "STRING",
+      time = ,
+      stop("Unsupported type", call. = FALSE)
+    )
+  }
+)

R/driver-impala.R

@@ -1,20 +1,29 @@
 #' @include dbi-connection.R
 NULL
 
+#' @export
+#' @rdname DBI-classes
+setClass("Impala", contains = "OdbcConnection")
+
 # TODO: Revisit binary type (Impala)
 #' @export
-`odbcDataType.Impala` <- function(con, obj, ...) {
-  switch_type(obj,
-    factor = "STRING",
-    datetime = "STRING",
-    date = "VARCHAR(10)",
-    integer = "INT",
-    int64 = "INT",
-    double = "DOUBLE",
-    character = "STRING",
-    logical = "BOOLEAN",
-    list = "STRING",
-    time = ,
-    stop("Unsupported type", call. = FALSE)
-  )
-}
+#' @rdname odbcDataType
+#' @usage NULL
+setMethod("odbcDataType", "Impala",
+  function(con, obj, ...) {
+    switch_type(
+      obj,
+      factor = "STRING",
+      datetime = "STRING",
+      date = "VARCHAR(10)",
+      integer = "INT",
+      int64 = "INT",
+      double = "DOUBLE",
+      character = "STRING",
+      logical = "BOOLEAN",
+      list = "STRING",
+      time = ,
+      stop("Unsupported type", call. = FALSE)
+    )
+  }
+)