OceanBase 数据库中引号对表标识符的影响

"OCEANBASE"    oceanbase    OCEANBASE    OceanBase

"oceanbase"    "OceanBase" "OCEANBASE"

create table t_case("code" VARCHAR2(10), "NAME" VARCHAR2(10));

SELECT "code" FROM t_case;
SELECT NAME FROM t_case;    
SELECT name FROM t_case;
SELECT "NAME" FROM t_case;
SELECT * FROM t_case "T" where t.name<>'a';    -- 表别名使用符合规则
SELECT * FROM t_case "t" where "t".name<>'a';    -- 表别名使用符合规则
SELECT "NAME" nm FROM t_case;    -- 字段别名符合规则
SELECT "NAME" "nm" FROM t_case;    -- 字段别名符合规则
select * from (SELECT "NAME" "nm" FROM t_case) where "nm"<>'a';    -- 字段别名符合规则

SELCT code FROM t_case;
SELCT "CODE" FROM t_case;
SELCT CODE FROM t_case;
SELECT "NAME" 'nm' FROM t_case;    -- 字段别名不符合规则，不能使用''
SELECT "NAME" nm FROM t_case where nm<>'a';;    -- 字段别名使用不符合规则，where条件中不能直接引用字段别名

`OCEANBASE`    `OceanBase`    oceanbase    OCEANBASE    OceanBase 

"oceanbase"    'oceanbase'

create table test (col_test1 int,`col_TEST2` varchar(50));

SELECT `col_TesT1`, col_test2 FROM test;

SELECT * FROM test t where `t`.col_test2<>'a';
SELECT * FROM test `T` where t.col_test2<>"a";

SELECT * FROM test 't' WHERE 't'.col_test1<>1;
SELECT * FROM test "t" WHERE "t".col_test1<>1;

SELECT col_test2 `ct` FROM test;
SELECT col_test2 ct FROM test;
SELECT col_test2 'ct' FROM test where "ct"<>"a";-- 前一个 ct 为字段别名命名，后一个 ct 为字段别名使用
SELECT col_test2 "ct" FROM test where 'ct'<>"a";
SELECT col_test2 `ct` FROM test where 'ct'<>"a";

SELECT col_test2 ct FROM test where ct<>"a";
SELECT col_test2 `ct` FROM test where `ct`<>"a";