Merge pull request #79 from pbondo/master.

Add JSON support for PostgreSQL with related test case.
Close #77
Close #79

src/backends/postgresql/statement.cpp

@@ -504,6 +504,7 @@ void postgresql_statement_backend::describe_column(int colNum, data_type & type,
     case 18:   // char
     case 1042: // bpchar
     case 142: // xml
+    case 114:  // json
     case 17: // bytea
         type = dt_string;
         break;

src/backends/postgresql/test/test-postgresql.cpp

@@ -629,6 +629,68 @@ struct table_creator_for_get_affected_rows : table_creator_base
     }
 };
 
+struct table_creator_json : public table_creator_base
+{
+    table_creator_json(session& sql)
+    : table_creator_base(sql)
+    {
+        sql << "drop table if exists soci_json_test;";
+        sql << "create table soci_json_test(data json)";
+    }
+};
+
+
+// Return 9,2 for 9.2.3
+typedef std::pair<int,int> server_version;
+
+server_version get_postgresql_version(session& sql)
+{
+    std::string version;
+    std::pair<int,int> result;
+    sql << "select version()",into(version);
+    if (sscanf(version.c_str(),"PostgreSQL %i.%i", &result.first, &result.second) < 2)
+    {
+        throw std::runtime_error("Failed to retrieve PostgreSQL version number");
+    }
+    return result;
+}
+
+// Test JSON. Only valid for PostgreSQL Server 9.2++
+void test_json()
+{
+    session sql(backEnd, connectString);
+    server_version version = get_postgresql_version(sql);
+    if ( version >= server_version(9,2))
+    {
+        bool exception = false;
+        std::string result;
+        std::string valid_input = "{\"tool\":\"soci\",\"result\":42}";
+        std::string invalid_input = "{\"tool\":\"other\",\"result\":invalid}";
+
+        table_creator_json tableCreator(sql);
+
+        sql << "insert into soci_json_test (data) values(:data)",use(valid_input);
+        sql << "select data from  soci_json_test",into(result);
+        assert(result == valid_input);
+
+        try
+        {
+            sql << "insert into soci_json_test (data) values(:data)",use(invalid_input);
+        }
+        catch(soci_error &_exception)
+        {
+            exception = true;
+        }
+        assert(exception);
+        std::cout << "test json passed" << std::endl;
+    }
+    else
+    {
+        std::cout << "json only available for PSQL server >= 9.2. Found version: " << version.first << "." << version.second << std::endl;
+    }
+}
+
+
 //
 // Support for soci Common Tests
 //
@@ -714,6 +776,7 @@ int main(int argc, char** argv)
         test11();
         test12();
         test_bytea();
+        test_json();
 
         std::cout << "\nOK, all tests passed.\n\n";
 

src/backends/postgresql/vector-into-type.cpp

@@ -167,7 +167,7 @@ void resizevector_(void * p, std::size_t sz)
 
 void postgresql_vector_into_type_backend::resize(std::size_t sz)
 {
-    assert(sz < std::numeric_limits<unsigned short>::max()); // Not a strong constraint, for debugging only
+    assert(sz < 10*std::numeric_limits<unsigned short>::max()); // Not a strong constraint, for debugging only. Notice my fix is even worse
 
     switch (type_)
     {