[libgda] postgres: ADD COLUMN supports IF NOT EXISTS

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 67e67ebb187fc3465c87503702f32a6a998ef239
Author: Daniel Espinosa Ortiz <esodan gmail com>
Date:   Wed Jan 9 11:48:00 2019 -0600

    postgres: ADD COLUMN supports IF NOT EXISTS
    
    Add support to IF EXISTS for table and IF NOT EXISTS
    for column to ADD COLUMN
    
    Fixed tests cases to add support to IF NOT EXISTS and
    IF EXISTS while checking meta data.
    
    Fix meta data generation while testing PostgreSQL connections.

 providers/postgres/gda-postgres-ddl.c              |  10 +-
 .../postgres/postgres_specs_add_column.xml.in      |   6 ++
 tests/providers/prov-test-common.c                 | 106 +++++++++++++--------
 3 files changed, 82 insertions(+), 40 deletions(-)
---
diff --git a/providers/postgres/gda-postgres-ddl.c b/providers/postgres/gda-postgres-ddl.c
index b2f0bbd11..bda319312 100644
--- a/providers/postgres/gda-postgres-ddl.c
+++ b/providers/postgres/gda-postgres-ddl.c
@@ -87,7 +87,7 @@ gda_postgres_render_DROP_DB (GdaServerProvider *provider, GdaConnection *cnc,
 {
        GString *string;
        gchar *sql = NULL;
-  GValue *value = NULL;
+  const GValue *value = NULL;
 
        string = g_string_new ("DROP DATABASE ");
 
@@ -490,6 +490,10 @@ gda_postgres_render_ADD_COLUMN (GdaServerProvider *provider, GdaConnection *cnc,
 
        string = g_string_new ("ALTER TABLE ");
 
+       value = gda_server_operation_get_value_at (op, "/COLUMN_DEF_P/TABLE_IFEXISTS");
+       if (value && G_VALUE_HOLDS (value, G_TYPE_BOOLEAN) && g_value_get_boolean (value))
+               g_string_append (string, "IF EXISTS ");
+
        value = gda_server_operation_get_value_at (op, "/COLUMN_DEF_P/TABLE_ONLY");
        if (value && G_VALUE_HOLDS (value, G_TYPE_BOOLEAN) && g_value_get_boolean (value))
                g_string_append (string, "ONLY ");
@@ -505,6 +509,10 @@ gda_postgres_render_ADD_COLUMN (GdaServerProvider *provider, GdaConnection *cnc,
 
        g_string_append (string, " ADD COLUMN ");
 
+       value = gda_server_operation_get_value_at (op, "/COLUMN_DEF_P/COLUMN_IFNOTEXISTS");
+       if (value && G_VALUE_HOLDS (value, G_TYPE_BOOLEAN) && g_value_get_boolean (value))
+               g_string_append (string, "IF NOT EXISTS ");
+
        tmp = gda_connection_operation_get_sql_identifier_at (cnc, op, "/COLUMN_DEF_P/COLUMN_NAME", error);
        if (!tmp) {
                g_string_free (string, TRUE);
diff --git a/providers/postgres/postgres_specs_add_column.xml.in 
b/providers/postgres/postgres_specs_add_column.xml.in
index f7b5d1c8c..2a7825b7b 100644
--- a/providers/postgres/postgres_specs_add_column.xml.in
+++ b/providers/postgres/postgres_specs_add_column.xml.in
@@ -5,12 +5,18 @@
     <parameter id="TABLE_ONLY" _name="Ignore descendants" _descr="Don't add the column to descendants of the 
table" gdatype="gboolean" nullok="TRUE">
       <gda_value>FALSE</gda_value>
     </parameter>
+    <parameter id="TABLE_IFEXISTS" _name="Only if it exist" _descr="Add column only if it exist" 
gdatype="gboolean" nullok="TRUE">
+      <gda_value>FALSE</gda_value>
+    </parameter>
     <parameter id="COLUMN_NAME" _name="Field name" gdatype="gchararray" nullok="FALSE">
       <gda_value>column_name</gda_value>
     </parameter>
     <parameter id="COLUMN_TYPE" _name="Data type" gdatype="gchararray" hint="datatype" nullok="FALSE">
       <gda_value>integer</gda_value>
     </parameter>
+    <parameter id="COLUMN_IFNOTEXISTS" _name="Only if it does not yet exist" _descr="Add column only if it 
does not yet exist" gdatype="gboolean" nullok="TRUE">
+      <gda_value>FALSE</gda_value>
+    </parameter>
     <parameter id="COLUMN_SIZE" _name="Size" gdatype="guint" nullok="TRUE"/>
     <parameter id="COLUMN_SCALE" _name="Scale" gdatype="guint" nullok="TRUE"/>
     <parameter id="COLUMN_NNUL" _name="Not NULL" gdatype="gboolean" nullok="TRUE">
diff --git a/tests/providers/prov-test-common.c b/tests/providers/prov-test-common.c
index 3cd08919b..7888b62f1 100644
--- a/tests/providers/prov-test-common.c
+++ b/tests/providers/prov-test-common.c
@@ -358,19 +358,19 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
         gda_server_operation_set_value_at (operation, "id", NULL, "/FIELDS_A/@COLUMN_NAME/0");
         gda_server_operation_set_value_at (operation, "int", NULL, "/FIELDS_A/@COLUMN_TYPE/0");
         gda_server_operation_set_value_at (operation, "TRUE", NULL, "/FIELDS_A/@COLUMN_PKEY/0");
-                               gchar *ops = gda_server_operation_render (operation, &error);
-                               if (ops == NULL) {
-                                       g_message ("Error while rendering operation to perform: %s",
-                                                                                error && error->message ? 
error->message : "No Error was set");
-                                       g_clear_error (&error);
-                                       return 1;
-                               }
-                               g_print ("Operation to perform: %s\n", ops);
-                               g_free (ops);
         if (! gda_server_provider_perform_operation (provider, cnc, operation, &error)) {
 #ifdef CHECK_EXTRA_INFO
                                        g_message ("perform_operation(CREATE_TABLE) failed: %s\n", error && 
error->message ?
-                                          error->message : "???");
+                                          error->message : "No error was set");
+                                       gchar *ops = gda_server_operation_render (operation, &error);
+                                       if (ops == NULL) {
+                                               g_message ("Error while rendering operation to perform: %s",
+                                                                                        error && 
error->message ? error->message : "No Error was set");
+                                               g_clear_error (&error);
+                                               return 1;
+                                       }
+                                       g_print ("Operation to perform: %s\n", ops);
+                                       g_free (ops);
 #endif
                 g_clear_error (&error);
                g_object_set (G_OBJECT (cnc), "options", options, NULL);
@@ -415,7 +415,7 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        g_assert (data);
        if (gda_data_model_get_n_rows (data) != 1) {
 #ifdef CHECK_EXTRA_INFO
-               g_message ("Getting Meta Tables: wrong number of rows : %d\n",
+               g_message ("Getting Meta Tables: wrong number of rows: expected 1 got: %d\n",
                gda_data_model_get_n_rows (data));
                gchar *sd1 = gda_data_model_dump_as_string (data);
                g_message ("Returned Data Model: \n%s", sd1);
@@ -453,13 +453,14 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        }
        if (gda_data_model_get_n_rows (data) != 1) {
 #ifdef CHECK_EXTRA_INFO
-               g_message ("Getting Meta for Fields: wrong number of rows : %d\n",
+               g_message ("Getting Meta for Fields: wrong number of rows: expected 1 got: %d\n",
                        gda_data_model_get_n_rows (data));
                gchar *sd3 = gda_data_model_dump_as_string (data);
                g_message ("Returned Data Model: \n%s", sd3);
                g_free (sd3);
 #endif
                gda_value_free (value);
+               gda_value_free (value2);
                g_object_unref (data);
                g_object_set (G_OBJECT (cnc), "options", options, NULL);
                return 1;
@@ -468,13 +469,14 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        g_assert (cvalue);
        if (gda_value_compare (value2, cvalue)) {
 #ifdef CHECK_EXTRA_INFO
-                g_message ("Comparing data for returned data in meta data for Fields: expected %s and got 
%s\n",
-                          gda_value_stringify (cvalue), gda_value_stringify (value));
+               g_message ("Comparing data for returned data in meta data for Fields: expected %s and got 
%s\n",
+                         gda_value_stringify (cvalue), gda_value_stringify (value));
                gchar *sd4 = gda_data_model_dump_as_string (data);
                g_message ("Returned Data Model: \n%s", sd4);
                g_free (sd4);
 #endif
                gda_value_free (value);
+               gda_value_free (value2);
                g_object_unref (data);
                g_object_set (G_OBJECT (cnc), "options", options, NULL);
                return 1;
@@ -485,32 +487,41 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
 
        /* ALTER table to add a column */
        operation = gda_server_provider_create_operation (provider, cnc,
-                                                         GDA_SERVER_OPERATION_ADD_COLUMN, NULL, &error);
-        g_assert (operation);
-        gda_server_operation_set_value_at_path (operation, table_name, "/COLUMN_DEF_P/TABLE_NAME", NULL);
-        gda_server_operation_set_value_at (operation, field_name, NULL, "/COLUMN_DEF_P/COLUMN_NAME", NULL);
-        gda_server_operation_set_value_at (operation, "int", NULL, "/COLUMN_DEF_P/COLUMN_TYPE", NULL);
-        if (! gda_server_provider_perform_operation (provider, cnc, operation, &error)) {
+                                                         GDA_SERVER_OPERATION_ADD_COLUMN, NULL, &error);
+       g_assert (operation);
+       gda_server_operation_set_value_at_path (operation, table_name, "/COLUMN_DEF_P/TABLE_NAME", NULL);
+       gda_server_operation_set_value_at (operation, "TRUE", NULL, "/COLUMN_DEF_P/TABLE_IFEXISTS");
+       gda_server_operation_set_value_at (operation, field_name, NULL, "/COLUMN_DEF_P/COLUMN_NAME", NULL);
+       gda_server_operation_set_value_at (operation, "int", NULL, "/COLUMN_DEF_P/COLUMN_TYPE", NULL);
+       gda_server_operation_set_value_at (operation, "TRUE", NULL, "/COLUMN_DEF_P/COLUMN_IFNOTEXISTS");
+                                       gchar *ops = gda_server_operation_render (operation, &error);
+                                       if (ops == NULL) {
+                                               g_message ("Error while rendering operation to perform: %s",
+                                                                                        error && 
error->message ? error->message : "No Error was set");
+                                               g_clear_error (&error);
+                                               return 1;
+                                       }
+                                       g_print ("Operation to perform: %s\n", ops);
+                                       g_free (ops);
+       if (! gda_server_provider_perform_operation (provider, cnc, operation, &error)) {
 #ifdef CHECK_EXTRA_INFO
-                g_message ("perform_operation(ADD_COLUMN) failed: %s\n", error && error->message ?
-                          error->message : "???");
-               gchar *sd5 = gda_data_model_dump_as_string (data);
-               g_message ("Returned Data Model: \n%s", sd5);
-               g_free (sd5);
+                                       g_message ("perform_operation(ADD_COLUMN) failed: %s\n", error && 
error->message ?
+                                          error->message : "No error was set");
 #endif
                 g_clear_error (&error);
-               g_object_set (G_OBJECT (cnc), "options", options, NULL);
-                return 1;
-        }
+                                       g_object_set (G_OBJECT (cnc), "options", options, NULL);
+                                       return 1;
+                               }
 
        /* update meta store */
 #ifdef CHECK_EXTRA_INFO
-       g_print ("Updating the complete meta store...\n");
+       g_print ("Updating the complete meta store after alter table...\n");
 #endif
+       g_value_set_string ((value2 = gda_value_new (G_TYPE_STRING)), "id");
        if (! gda_connection_update_meta_store (cnc, update_all ? NULL : &mcontext, &error)) {
 #ifdef CHECK_EXTRA_INFO
-               g_message ("Can't FULL update meta store: %s\n",
-                          error && error->message ? error->message : "???");
+               g_message ("Can't FULL update meta store after alter table: %s",
+                          error && error->message ? error->message : "No error was set");
 #endif
                g_clear_error (&error);
                g_object_set (G_OBJECT (cnc), "options", options, NULL);
@@ -519,7 +530,7 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
 
        /* check table */
 #ifdef CHECK_EXTRA_INFO
-       g_print ("Checking fetched meta data...\n");
+       g_print ("Checking fetched meta data after alter table...\n");
 #endif
        g_value_take_string ((value = gda_value_new (G_TYPE_STRING)),
                             gda_meta_store_sql_identifier_quote (table_name, cnc));
@@ -528,8 +539,8 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        g_assert (data);
        if (gda_data_model_get_n_rows (data) != 1) {
 #ifdef CHECK_EXTRA_INFO
-                g_message ("Getting meta data for Tables (2): wrong number of rows : %d\n",
-                          gda_data_model_get_n_rows (data));
+               g_message ("Getting meta data for Tables after alter: wrong number of rows: expected 1 got: 
%d\n",
+                         gda_data_model_get_n_rows (data));
                gchar *sd6 = gda_data_model_dump_as_string (data);
                g_message ("Returned Data Model: \n%s", sd6);
                g_free (sd6);
@@ -543,10 +554,10 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        g_assert (cvalue);
        if (gda_value_compare (value, cvalue)) {
 #ifdef CHECK_EXTRA_INFO
-               g_message ("Comparing data in meta data fro tables: expected %s and got %s\n",
+               g_message ("Mismatch table's name in meta data after alter table: expected %s and got %s\n",
                           gda_value_stringify (cvalue), gda_value_stringify (value));
                gchar *sd6a = gda_data_model_dump_as_string (data);
-               g_message ("Returned Data Model: \n%s", sd6a);
+               g_message ("Returned Data Model after alter: \n%s", sd6a);
                g_free (sd6a);
 #endif
                gda_value_free (value);
@@ -557,21 +568,36 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        g_object_unref (data);
 
        /* check fields of table */
+       g_value_take_string ((value = gda_value_new (G_TYPE_STRING)),
+                            gda_meta_store_sql_identifier_quote (table_name, cnc));
        g_value_take_string ((value2 = gda_value_new (G_TYPE_STRING)),
                             gda_meta_store_sql_identifier_quote (field_name, cnc));
        data = gda_connection_get_meta_store_data (cnc, GDA_CONNECTION_META_FIELDS, &error, 2,
                                                   "name", value, "field_name", value2);
+       g_print ("Searching for column's name: '%s'", gda_value_stringify (value2));
        g_assert (data);
        if (gda_data_model_get_n_rows (data) != 1) {
 #ifdef CHECK_EXTRA_INFO
-               g_message ("Getting meta data for Fields: wrong number of rows : %d\n",
+               g_message ("Getting meta data for Fields after alter: wrong number of rows: expected 1 got: 
%d\n",
                           gda_data_model_get_n_rows (data));
                gchar *sd7 = gda_data_model_dump_as_string (data);
                g_message ("Returned Data Model: \n%s", sd7);
                g_free (sd7);
+               g_object_unref (data);
+               data = gda_connection_get_meta_store_data (cnc, GDA_CONNECTION_META_FIELDS, &error, 1,
+                                                          "name", value);
+               if (data != NULL) {
+                       sd7 = gda_data_model_dump_as_string (data);
+                       g_message ("Returned Data Model: \n%s", sd7);
+                       g_free (sd7);
+                       g_object_unref (data);
+               } else {
+                       g_message ("Error getting all fields: %s",
+                                 error && error->message ? error->message : "No error was set");
+               }
 #endif
                gda_value_free (value);
-               g_object_unref (data);
+               gda_value_free (value2);
                g_object_set (G_OBJECT (cnc), "options", options, NULL);
                return 1;
        }
@@ -579,18 +605,20 @@ prov_test_common_check_meta_identifiers (gboolean case_sensitive, gboolean updat
        g_assert (cvalue);
        if (gda_value_compare (value2, cvalue)) {
 #ifdef CHECK_EXTRA_INFO
-               g_message ("Comparing meta data from Fields: expected %s and got %s\n",
+               g_message ("Mismatch column's name in meta data: expected %s and got %s\n",
                           gda_value_stringify (cvalue), gda_value_stringify (value));
                gchar *sd8 = gda_data_model_dump_as_string (data);
                g_message ("Returned Data Model: \n%s", sd8);
                g_free (sd8);
 #endif
                gda_value_free (value);
+               gda_value_free (value2);
                g_object_unref (data);
                g_object_set (G_OBJECT (cnc), "options", options, NULL);
                return 1;
        }
        gda_value_free (value);
+       gda_value_free (value2);
        g_object_unref (data);
 
        g_object_set (G_OBJECT (cnc), "options", options, NULL);