SQL Server to PostgreSQL equivalent

I need some help in converting or equivalent of below in postgreSQL..

From MSSQL code to postgreSQL:-

1. CONVERT(bit,CASE WHEN column_a & 1 > 0 THEN 1 ELSE 0 END) as ABC, 2. CONVERT(tinyint,CASE WHEN column_a IS NOT NULL THEN 0  END) as ABC 3. CONVERT(smallint,CASE WHEN col_year = (SELECT year(col_date)      FROM tab A WHERE A.a = 192) THEN 1 ELSE 0 END) as ABC, 4. TO_CHAR(TO_CHAR(YEAR(Date))||'Y') as ABC 5. CASE WHEN COL_A = 1 THEN TO_CHAR(YEAR(Date))||'Y'  6. WHEN COL_A = 4 THEN TO_CHAR (YEAR(Date) ) || 'Q' || TO_CHAR(Month(Date)/3 ) ELSE NULL END as ABC 

Please help..