added customDatatype for correct text mapping (#51)

README.md

@@ -36,7 +36,7 @@ See [getJdbcCatalogName](#getJdbcCatalogName)
 
 The `datetime` datatype in Snowflake is an alias for the datatype `timestamp_ntz`, [Date and Time Data Types](https://docs.snowflake.net/manuals/sql-reference/data-types.html#date-and-time-data-types).
 The `TimestampNTZType` class clarifies this mapping from Liquibase `datetime` to Snowflake `timestamp_ntz`.
-
+To map `text` datatype in changesets to `text` Snowflake datatype SnowflakeTextDataType class is added (default liquibase-core classes maps it to `CLOB`)
 
 ## ChangeLog
 

src/main/java/liquibase/ext/snowflake/datatype/SnowflakeTextDataType.java

@@ -0,0 +1,30 @@
+package liquibase.ext.snowflake.datatype;
+
+import liquibase.change.core.LoadDataChange;
+import liquibase.database.Database;
+import liquibase.datatype.DataTypeInfo;
+import liquibase.datatype.DatabaseDataType;
+import liquibase.datatype.LiquibaseDataType;
+import liquibase.ext.snowflake.database.SnowflakeDatabase;
+
+@DataTypeInfo(name = "text", minParameters = 0, maxParameters = 0, priority = LiquibaseDataType.PRIORITY_DATABASE)
+public class SnowflakeTextDataType extends LiquibaseDataType {
+
+    @Override
+    public boolean supports(Database database) {
+        return database instanceof SnowflakeDatabase;
+    }
+
+    @Override
+    public DatabaseDataType toDatabaseDataType(Database database) {
+        if (database instanceof SnowflakeDatabase) {
+            return new DatabaseDataType("TEXT", getParameters());
+        }
+        return super.toDatabaseDataType(database);
+    }
+
+    @Override
+    public LoadDataChange.LOAD_DATA_TYPE getLoadTypeName() {
+        return LoadDataChange.LOAD_DATA_TYPE.STRING;
+    }
+}

src/main/resources/META-INF/services/liquibase.datatype.LiquibaseDataType

@@ -1 +1,2 @@
 liquibase.ext.snowflake.datatype.TimestampNTZType
+liquibase.ext.snowflake.datatype.SnowflakeTextDataType

src/test/resources/liquibase/harness/change/expectedSql/snowflake/createTableDataTypeText.sql

@@ -0,0 +1 @@
+CREATE TABLE createTableDataTypeText (textCol TEXT)