feat: dm_from_con(learn_keys = TRUE) works for MariaDB

DESCRIPTION

@@ -78,7 +78,7 @@ Suggests:
     pixarfilms,
     pool,
     progress,
-    RMariaDB (>= 1.0.10),
+    RMariaDB (>= 1.2.2),
     rmarkdown,
     RPostgres,
     RSQLite (>= 2.2.8),

R/db-helpers.R

@@ -91,7 +91,7 @@ repair_table_names_for_db <- function(table_names, temporary, con, schema = NULL
     names <- unique_db_table_name(names)
   } else {
     # permanent tables
-    if (!is.null(schema) && !is_mssql(con) && !is_postgres(con)) {
+    if (!is.null(schema) && !is_mssql(con) && !is_postgres(con) && !is_mariadb(con)) {
       abort_no_schemas_supported(con = con)
     }
     names <- table_names

R/global.R

@@ -164,6 +164,11 @@ utils::globalVariables(c(
   "remote_table_unquoted",
   "unique_def",
   #
+  # meta
+  "referenced_column_name",
+  "referenced_table_name",
+  "referenced_table_schema",
+  #
   # keep this to avoid dealing with trailing commas
   NULL
 ))

R/meta.R

@@ -45,31 +45,50 @@ dm_meta_raw <- function(con, catalog) {
 
   local_options(digits.secs = 6)
 
-  schemata <- tbl_lc(src, "information_schema.schemata", vars = c(
-    "catalog_name", "schema_name", "schema_owner", "default_character_set_catalog",
-    "default_character_set_schema", "default_character_set_name"
+  schemata <- tbl_lc(src, "information_schema.schemata", vars = vec_c(
+    "catalog_name", "schema_name", "default_character_set_name",
+    # Optional, not MySQL:
+    # "schema_owner", "default_character_set_catalog", "default_character_set_schema",
   ))
-  tables <- tbl_lc(src, "information_schema.tables", vars = c(
-    "table_catalog", "table_schema", "table_name", "table_type"
+  tables <- tbl_lc(src, "information_schema.tables", vars = vec_c(
+    "table_catalog", "table_schema", "table_name", "table_type",
   ))
-  columns <- tbl_lc(src, "information_schema.columns", vars = c(
+  columns <- tbl_lc(src, "information_schema.columns", vars = vec_c(
     "table_catalog", "table_schema", "table_name", "column_name",
     "ordinal_position", "column_default", "is_nullable", "data_type",
     "character_maximum_length", "character_octet_length", "numeric_precision",
-    "numeric_precision_radix", "numeric_scale", "datetime_precision",
-    "character_set_catalog", "character_set_schema", "character_set_name",
-    "collation_catalog", "collation_schema", "collation_name", "domain_catalog",
-    "domain_schema", "domain_name"
-  ))
-  table_constraints <- tbl_lc(src, "information_schema.table_constraints", vars = c(
-    "constraint_catalog", "constraint_schema", "constraint_name",
-    "table_catalog", "table_schema", "table_name", "constraint_type",
-    "is_deferrable", "initially_deferred"
+    "numeric_scale", "datetime_precision",
+    "character_set_name", "collation_name",
+
+    # Optional, not RMySQL:
+    # "numeric_precision_radix",
+    # "character_set_catalog", "character_set_schema",
+    # "collation_catalog", "collation_schema", "domain_catalog",
+    # "domain_schema", "domain_name"
   ))
-  key_column_usage <- tbl_lc(src, "information_schema.key_column_usage", vars = c(
+
+  if (is_mariadb(src)) {
+    table_constraints <- tbl_lc(src, "information_schema.table_constraints", vars = vec_c(
+      "constraint_catalog", "constraint_schema", "constraint_name",
+      "table_name", "constraint_type"
+    )) %>%
+      mutate(table_catalog = constraint_catalog, table_schema = constraint_schema, .before = table_name) %>%
+      mutate(constraint_name = if_else(constraint_type == "PRIMARY KEY", paste0("pk_", table_name), constraint_name)) %>%
+      # WAT
+      mutate(constraint_schema = tolower(constraint_schema)) %>%
+      mutate(table_schema = tolower(table_schema))
+  } else {
+    table_constraints <- tbl_lc(src, "information_schema.table_constraints", vars = vec_c(
+      "constraint_catalog", "constraint_schema", "constraint_name",
+      "table_catalog", "table_schema", "table_name", "constraint_type",
+      "is_deferrable", "initially_deferred",
+    ))
+  }
+
+  key_column_usage <- tbl_lc(src, "information_schema.key_column_usage", vars = vec_c(
     "constraint_catalog", "constraint_schema", "constraint_name",
     "table_catalog", "table_schema", "table_name", "column_name",
-    "ordinal_position"
+    "ordinal_position",
   ))
 
   if (is_postgres(src)) {
@@ -82,6 +101,39 @@ dm_meta_raw <- function(con, catalog) {
       ))
   } else if (is_mssql(src)) {
     constraint_column_usage <- mssql_constraint_column_usage(src, table_constraints, catalog)
+  } else {
+    # Alternate constraint names for uniqueness
+    key_column_usage <-
+      key_column_usage %>%
+      left_join(
+        tbl_lc(src, "information_schema.table_constraints", vars = vec_c(
+          "constraint_catalog", "constraint_schema", "constraint_name",
+          "table_name", "constraint_type"
+        )),
+        by = vec_c(
+          "constraint_catalog", "constraint_schema", "constraint_name",
+          "table_name",
+        )
+      ) %>%
+      mutate(constraint_name = if_else(constraint_type == "PRIMARY KEY", paste0("pk_", table_name), constraint_name)) %>%
+      select(-constraint_type)
+
+    constraint_column_usage <-
+      tbl_lc(src, "information_schema.key_column_usage", vars = c(
+        "table_catalog",
+        "referenced_table_schema", "referenced_table_name", "referenced_column_name",
+        "constraint_catalog", "constraint_schema", "constraint_name",
+        "ordinal_position"
+      )) %>%
+      filter(!is.na(referenced_table_name)) %>%
+      rename(
+        table_schema = referenced_table_schema,
+        table_name = referenced_table_name,
+        column_name = referenced_column_name,
+      ) %>%
+      # WAT
+      mutate(constraint_schema = tolower(constraint_schema)) %>%
+      mutate(table_schema = tolower(table_schema))
   }
 
   dm(schemata, tables, columns, table_constraints, key_column_usage, constraint_column_usage) %>%
@@ -145,13 +197,24 @@ dm_meta_simple_add_keys <- function(dm_meta) {
 }
 
 tbl_lc <- function(con, name, vars) {
-  from <- paste0(
-    "SELECT ",
-    paste0(DBI::dbQuoteIdentifier(con_from_src_or_con(con), vars), collapse = ", "),
-    "\nFROM ", name
-  )
+  # For discovery only!
+  if (is.null(vars)) {
+    from <- name
+  } else {
+    from <- sql(paste0(
+      "SELECT ",
+      paste0(DBI::dbQuoteIdentifier(con_from_src_or_con(con), vars), collapse = ", "),
+      "\nFROM ", name
+    ))
+  }
 
-  tbl(con, sql(from), vars = vars)
+  out <- tbl(con, from, vars = vars)
+  if (is.null(vars)) {
+    out <-
+      out %>%
+      rename(!!!set_names(colnames(out), tolower(colnames(out))))
+  }
+  out
 }
 
 select_dm_meta <- function(dm_meta) {