Query below lists table check constraints.
Query
select con.tabschema concat '.' concat con.tabname as table,
    col.colname as column_name,
    con.text  as definition,
    case tab.enforced 
      when 'N' then 'disabled'
      when 'Y' then 'active'
    end as status,
    con.constname as constraint_name
from syscat.checks con
join syscat.colchecks col on col.constname = con.constname 
        and col.tabschema = con.tabschema 
        and col.tabname = con.tabname
join syscat.tabconst tab on tab.constname = con.constname 
        and tab.tabschema = con.tabschema 
        and tab.tabname = con.tabname
where con.tabschema not like 'SYS%'
order by con.tabschema concat '.' concat con.tabname,
    col.colname
Columns
- table - schema and table name
- column_name - name of the column
- definition - SQL expression that defines this check constraint
- status - constraint status:
- 'active' if constraint is active,
- 'disabled' for disabled constraints
 
- constraint_name - name of the constraint in the database
Rows
- One row represents one check constraint or column. If check constraint consists of multiple columns (table-level check constraints), each column appears separately
- Scope of rows: query returns all check constraints in the database
- Ordered by table schema and name, column name
Sample results

 
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                 
                                                             
                                                             
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                             
                                                             Marcin Nagly
                                                                        Marcin Nagly
                                 IBM Db2
                                                                IBM Db2
                                 SQL Server
                                                                                                SQL Server
                                             Azure SQL Database
                                                                                                Azure SQL Database
                                             Oracle database
                                                                                                Oracle database
                                             Teradata
                                                                                                Teradata
                                             PostgreSQL
                                                                                                PostgreSQL
                                             MariaDB
                                                                                                MariaDB