use dbCreateTable() and dbAppendTable()

- Using `dbCreateTable()` and `dbAppendTable()` internally (r-dbi/DBI#74).
r-dbi · Apr 25, 2018 · 9087470 · 9087470
1 parent 4caf449
commit 9087470
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Showing 4 changed files with 35 additions and 22 deletions.
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -19,7 +19,7 @@ Depends:
     R (>= 2.8.0)
 Imports: 
     bit64,
-    DBI (>= 0.8),
+    DBI (>= 0.8.0.9001),
     hms,
     methods,
     Rcpp (>= 0.12.4)

diff --git a/NAMESPACE b/NAMESPACE
@@ -26,13 +26,15 @@ export(mariadbHasDefault)
 exportClasses(MariaDBConnection)
 exportClasses(MariaDBDriver)
 exportClasses(MariaDBResult)
+exportMethods(dbAppendTable)
 exportMethods(dbBegin)
 exportMethods(dbBind)
 exportMethods(dbCanConnect)
 exportMethods(dbClearResult)
 exportMethods(dbColumnInfo)
 exportMethods(dbCommit)
 exportMethods(dbConnect)
+exportMethods(dbCreateTable)
 exportMethods(dbDataType)
 exportMethods(dbDisconnect)
 exportMethods(dbDriver)

diff --git a/R/export.R b/R/export.R
@@ -5,6 +5,9 @@
 #   paste0("#' @exportMethod ", ., "\nNULL\n", collapse = "\n") %>%
 #   cat(file = "R/export.R")
 
+#' @exportMethod dbAppendTable
+NULL
+
 #' @exportMethod dbBegin
 NULL
 
@@ -26,6 +29,9 @@ NULL
 #' @exportMethod dbConnect
 NULL
 
+#' @exportMethod dbCreateTable
+NULL
+
 #' @exportMethod dbDataType
 NULL
 

diff --git a/R/table.R b/R/table.R
@@ -97,8 +97,11 @@ setMethod("dbWriteTable", c("MariaDBConnection", "character", "data.frame"),
     if (overwrite && append) {
       stopc("overwrite and append cannot both be TRUE")
     }
+    if (!is.null(field.types) && !(is.character(field.types) && !is.null(names(field.types)) && !anyDuplicated(names(field.types)))) {
+      stopc("`field.types` must be a named character vector with unique names, or NULL")
+    }
     if (append && !is.null(field.types)) {
-      stopc("Cannot specify field.types with append = TRUE")
+      stopc("Cannot specify `field.types` with `append = TRUE`")
     }
 
     need_transaction <- !connection_is_transacting(conn@ptr)
@@ -121,32 +124,34 @@ setMethod("dbWriteTable", c("MariaDBConnection", "character", "data.frame"),
       dbRemoveTable(conn, name, temporary = temporary, fail_if_missing = FALSE)
     }
 
+    value <- sql_data(value[, , drop = FALSE], row.names)
+
     if (!found || overwrite) {
-      sql <- sqlCreateTable(
-        conn,
-        name,
-        if (is.null(field.types)) value else field.types,
-        row.names = row.names,
+      if (is.null(field.types)) {
+        combined_field_types <- lapply(value, dbDataType, dbObj = conn)
+      } else {
+        combined_field_types <- rep("", length(value))
+        names(combined_field_types) <- names(value)
+        field_types_idx <- match(names(field.types), names(combined_field_types))
+        stopifnot(!any(is.na(field_types_idx)))
+        combined_field_types[field_types_idx] <- field.types
+        values_idx <- setdiff(seq_along(value), field_types_idx)
+        combined_field_types[values_idx] <- lapply(value[values_idx], dbDataType, dbObj = conn)
+      }
+
+      dbCreateTable(
+        conn = conn,
+        name = name,
+        fields = combined_field_types,
         temporary = temporary
       )
-      dbExecute(conn, sql)
     }
 
     if (nrow(value) > 0) {
-      values <- sql_data(value[, , drop = FALSE], row.names)
-
-      name <- dbQuoteIdentifier(conn, name)
-      fields <- dbQuoteIdentifier(conn, names(values))
-      params <- rep("?", length(fields))
-
-      sql <- paste0(
-        "INSERT INTO ", name, " (", paste0(fields, collapse = ", "), ")\n",
-        "VALUES (", paste0(params, collapse = ", "), ")"
-      )
-      rs <- dbSendStatement(conn, sql)
-      tryCatch(
-        result_bind(rs@ptr, values),
-        finally = dbClearResult(rs)
+      dbAppendTable(
+        conn = conn,
+        name = name,
+        values = value
       )
     }