Using CASE on WHERE clause?

Question

Is it posible to use a CASE on the WHERE clause?
I always used the following syntax on MSSQL
but Oracle aparently doesn't accept it:
SELECT...
WHERE
     CASE WHEN keyword IS NOT NULL THEN
          CONTAINS(field, keyword) > 0
     END AND
     CASE WHEN varcode IS NOT NULL THEN
          code = varcode
     END AND
     OTHER STATEMENTS

Answer 1

SQL> SELECT
2 COUNT(*) OVER() total,
3 ed_fotos.id AS COD_FOTO,
4 ed_fotos.foto.getwidth()/100 AS VLR_LARGURA,
5 ed_fotos.foto.getheight()/100 AS VLR_ALTURA,
6 ed_fotos.arquivo AS NOM_ARQUIVO,
7 ed_areas.nome AS NOM_REDACAO
8 FROM edt.ed_fotos ed_fotos
9 INNER JOIN edt.ed_areas ed_areas ON
10 ed_areas.id = ed_fotos.redacao_id AND
11 (ed_areas.ind_licenciada <> 'S' OR
12 ed_areas.ind_licenciada IS NULL
13 OR (ed_areas.id IN (SELECT * FROM THE (SELECT CAST(fda_
adm.in_list('') AS fda_adm.mytableType) FROM dual)))
14 )
15 LEFT JOIN edt.ed_creditos_fotos ed_creditos_fotos ON
16 ed_creditos_fotos.foto_id = ed_fotos.id
17 LEFT JOIN edt.ed_itens ed_itens ON
18 ed_itens.foto_id = ed_fotos.id
19 LEFT JOIN edt.ed_edicoes ed_edicoes ON
20 ed_edicoes.id = ed_itens.edicao_id
21 LEFT JOIN edt.vw_dedoc_ccda vw_dedoc_ccda ON
22 vw_dedoc_ccda.num_ccda = ed_fotos.num_ccda_sct AND
23 vw_dedoc_ccda.cod_tipo_documento IN ('B','C','C1','C2')
24 LEFT JOIN fda_adm.vw_lui vw_lui ON
25 vw_lui.foto_id = ed_fotos.id AND
26 vw_lui.cod_tipo_documento IN ('B','C')
27 WHERE
28 CASE WHEN 'BUSH' IS NOT NULL THEN
29 CONTAINS(ed_fotos.detalhe, '{BUSH} within termo
OR {BUSH} within headline OR {BUSH} within desc') > 0
30 END) AND
31 1 = 1
32 GROUP BY
33 ed_fotos.id,
34 ed_fotos.foto.getwidth(),
35 ed_fotos.foto.getheight(),
36 ed_fotos.registro,
37 ed_fotos.arquivo,
38 ed_areas.nome,
39 ed_areas.id
40 ORDER BY
41 ed_fotos.id DESC
42 /
CONTAINS(ed_fotos.detalhe, '{BUSH} within termo
OR {BUSH} within headline OR {BUSH} within desc') > 0
ERRO on line 29:
ORA-00905: missing keyword