Adding 'CONSTRAINT ensure_json CHECK (po_document IS JSON))' in liquibase - liquibase

Question

I want to add check constraint to BLOB type column which stores JSON data, in CREATE Table script in liquibase(version 3.3.5, database -Oracle 12C). but it does not compile. Can anyone please explain what is the right syntax to add constraint which ensures only JSON type data would be inserted. I followed this question
Plain sql : CONSTRAINT ensure_json CHECK (po_document IS JSON))
But not sure what is liquibase equivalent for this.
PostgreSQL Check Constraint in Liquibase
<changeSet id="Change_id" author="xqz">
<createTable tableName="table_name">
<column name="pkey" type="int">
<constraints primaryKey="true"/>
</column>
<column name="table2_pkey" type="int">
<constraints nullable="false"/>
</column>
<column name="name" type="varchar(100)">
<constraints nullable="false"/>
</column>
<column name="filters" type="BLOB">
<constraints checkConstraint="ensure_json CHECK (filters IS JSON)" />
</column>
</createTable>
</changeSet>
If I add constraint to filters column, build fails, If I remove it, build is successful. What am I doing wrong. I could not find syntax for it in liquibase docs.

Answer 1

You cannot define check constraints in liquibase, for aditional information see this forum entry.
You'll have to use an <sql> tag like
<sql dbms=oracle>
CREATE TABLE table_name (
pkey integer PRIMARY KEY,
table2_pkey integer NOT NULL,
name varchar(100) NOT NULL,
flter blob CONSTRAINT ensure_json CHECK (filters IS JSON)
)
</sql>
Should work just the same, except that you have to add your own <rollback> tag.