原生openGauss与Oracle数据库函数兼容性对比验证测试

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一、测试目的

近期在进行调研去O,为此研究了下原生openGauss和Oracle数据库兼容性，特整理测试了Oracle常用函数和openGauss数据库的对比测试。

二、创建DUAL虚拟表

openGauss 数据库不提供DUAL虚拟表，需要通过如下方式创建视图模拟dual虚拟表：

create or replace view dual as
select NULL::"unknown"
where 1=1;

alter table dual owner to 连接用户名;
grant all on table dual to 连接用户名;
grant select on table dual to public;

三、测试结果

测试语句及结果如下：

序号	函数名称	查询语句	openGauss查询结果	Oracle查询结果	是否兼容
1	`ASCII`	SELECT ASCII('A') FROM DUAL;	openGauss=# SELECT ASCII('A') FROM DUAL; ascii ------- 65 (1 row)	SQL> SELECT ASCII('A') FROM DUAL; ASCII('A') ---------- 65	支持
2	`CHR`	SELECT CHR(65) FROM DUAL;	openGauss=# SELECT CHR(65) FROM DUAL; chr ----- A (1 row)	SQL> SELECT CHR(65) FROM DUAL; C - A	支持
3	`CONCAT`		openGauss=# SELECT CONCAT(CONCAT('Hello', ' '), 'World') FROM DUAL; concat ------------- Hello World (1 row)	SQL> SELECT CONCAT(CONCAT('Hello', ' '), 'World') FROM DUAL; CONCAT(CONC ----------- Hello World	支持
4	`INITCAP`	SELECT INITCAP('hello world') FROM DUAL;	openGauss=# SELECT INITCAP('hello world') FROM DUAL; initcap ------------- Hello World (1 row)	SQL> SELECT INITCAP('hello world') FROM DUAL; INITCAP('HE ----------- Hello World	支持
5	`INSTR`	SELECT INSTR('Hello World', 'o') FROM DUAL;	openGauss=# SELECT INSTR('Hello World', 'o') FROM DUAL; instr ------- 5 (1 row	SQL> SELECT INSTR('Hello World', 'o') FROM DUAL; INSTR('HELLOWORLD','O') ----------------------- 5	支持
6	`LENGTH`	SELECT LENGTH('Hello') FROM DUAL;	openGauss=# SELECT LENGTH('Hello') FROM DUAL; length -------- 5 (1 row)	SQL> SELECT LENGTH('Hello') FROM DUAL; LENGTH('HELLO') --------------- 5	支持
7	`LOWER`	SELECT LOWER('Hello') FROM DUAL;	openGauss=# SELECT LOWER('Hello') FROM DUAL; lower ------- hello (1 row)	SQL> SELECT LOWER('Hello') FROM DUAL; LOWER ----- hello	支持
8	`UPPER`	SELECT UPPER('Hello') FROM DUAL;	openGauss=# SELECT UPPER('Hello') FROM DUAL; upper ------- HELLO (1 row)	SQL> SELECT UPPER('Hello') FROM DUAL; UPPER ----- HELLO	支持
9	`RPAD and LPAD`	SELECT RPAD('Hello', 10, ' ') FROM DUAL; SELECT LPAD('Hello', 10, ' ') FROM DUAL;	openGauss=# SELECT RPAD('Hello', 10, ' ') FROM DUAL; rpad ------------ Hello (1 row) openGauss=# SELECT LPAD('Hello', 10, ' ') FROM DUAL; lpad ------------ Hello (1 row)	SQL> SELECT RPAD('Hello', 10, ' ') FROM DUAL; RPAD('HELL ---------- Hello SQL> SELECT LPAD('Hello', 10, ' ') FROM DUAL; LPAD('HELL ---------- Hello	支持
10	`LTRIM and RTRIM`	SELECT LTRIM(' Hello ') FROM DUAL; SELECT RTRIM(' Hello ') FROM DUAL;	openGauss=# SELECT LTRIM(' Hello ') FROM DUAL; ltrim ---------- Hello (1 row) openGauss=# SELECT RTRIM(' Hello ') FROM DUAL; rtrim ---------- Hello (1 row)	SQL> SELECT LTRIM(' Hello ') FROM DUAL; LTRIM('H -------- Hello SQL> SELECT RTRIM(' Hello ') FROM DUAL; RTRIM('H -------- Hello	支持
11	`SUBSTR`	SELECT SUBSTR('Hello World', 7, 5) FROM DUAL;	openGauss=# SELECT SUBSTR('Hello World', 7, 5) FROM DUAL; substr -------- World (1 row)	SQL> SELECT SUBSTR('Hello World', 7, 5) FROM DUAL; SUBST ----- World	支持
12	`REPLACE`		openGauss=# SELECT REPLACE('Hello World', 'o', 'a') FROM DUAL; replace ------------- Hella Warld (1 row)	SQL> SELECT REPLACE('Hello World', 'o', 'a') FROM DUAL; REPLACE('HE ----------- Hella Warld	支持
13	`SOUNDEX`	SELECT SOUNDEX('Hello') FROM DUAL;	openGauss=# SELECT SOUNDEX('Hello') FROM DUAL; ERROR: function soundex(unknown) does not exist LINE 1: SELECT SOUNDEX('Hello') FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: soundex	SQL> SELECT SOUNDEX('Hello') FROM DUAL; SOUN ---- H400	不支持
14	`TRIM`	SELECT TRIM(' Hello ') FROM DUAL;	openGauss=# SELECT TRIM(' Hello ') FROM DUAL; btrim ------- Hello (1 row)	SQL> SELECT TRIM(' Hello ') FROM DUAL; TRIM( ----- Hello	支持
15	`ACOS`	SELECT ACOS(0) FROM DUAL;	openGauss=# SELECT ACOS(0) FROM DUAL; acos ----------------- 1.5707963267949 (1 row)	SQL> SELECT ACOS(0) FROM DUAL; ACOS(0) ---------- 1.57079633	支持
16	`ASIN`	SELECT ASIN(0) FROM DUAL;	openGauss=# SELECT ASIN(0) FROM DUAL; asin ------ 0 (1 row)	SQL> SELECT ASIN(0) FROM DUAL; ASIN(0) ---------- 0	支持
17	`ATAN`	SELECT ATAN(1) FROM DUAL;	openGauss=# SELECT ATAN(1) FROM DUAL; atan ------------------ .785398163397448 (1 row)	SQL> SELECT ATAN(1) FROM DUAL; ATAN(1) ---------- .785398163	支持
18	`CEIL`	SELECT CEIL(3.14) FROM DUAL;	openGauss=# SELECT CEIL(3.14) FROM DUAL; ceil ------ 4 (1 row)	SQL> SELECT CEIL(3.14) FROM DUAL; CEIL(3.14) ---------- 4	支持
19	`COS`	SELECT COS(0) FROM DUAL;	openGauss=# SELECT COS(0) FROM DUAL; cos ----- 1 (1 row)	SQL> SELECT COS(0) FROM DUAL; COS(0) ---------- 1	支持
20	`COSH`	SELECT COSH(0) FROM DUAL;	openGauss=# SELECT COSH(0) FROM DUAL; ERROR: function cosh(integer) does not exist LINE 1: SELECT COSH(0) FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: cosh	SQL> SELECT COSH(0) FROM DUAL; COSH(0) ---------- 1	不支持
21	`EXP`	SELECT EXP(1) FROM DUAL;	openGauss=# SELECT EXP(1) FROM DUAL; exp ------------------ 2.71828182845905 (1 row)	SQL> SELECT EXP(1) FROM DUAL; EXP(1) ---------- 2.71828183	支持
22	`FLOOR`	SELECT FLOOR(3.14) FROM DUAL;	openGauss=# SELECT FLOOR(3.14) FROM DUAL; floor ------- 3 (1 row)	SQL> SELECT FLOOR(3.14) FROM DUAL; FLOOR(3.14) ----------- 3	支持
23	`LN`	SELECT LN(2) FROM DUAL;	openGauss=# SELECT LN(2) FROM DUAL; ln ------------------ .693147180559945 (1 row)	SQL> SELECT LN(2) FROM DUAL; LN(2) ---------- .693147181	支持
24	`LOG`	SELECT LOG(10, 100) FROM DUAL;	openGauss=# SELECT LOG(10, 100) FROM DUAL; log -------------------- 2.0000000000000000 (1 row)	SQL> SELECT LOG(10, 100) FROM DUAL; LOG(10,100) ----------- 2	支持
25	`MOD`	SELECT MOD(10, 3) FROM DUAL;	openGauss=# SELECT MOD(10, 3) FROM DUAL; mod ----- 1 (1 row)	SQL> SELECT MOD(10, 3) FROM DUAL; MOD(10,3) ---------- 1	支持
26	`POWER`	SELECT POWER(2, 3) FROM DUAL;	openGauss=# SELECT POWER(2, 3) FROM DUAL; power ------- 8 (1 row)	SQL> SELECT POWER(2, 3) FROM DUAL; POWER(2,3) ---------- 8	支持
27	`ROUND and TRUNC`	SELECT ROUND(3.14) FROM DUAL; SELECT TRUNC(3.14) FROM DUAL;	openGauss=# SELECT ROUND(3.14) FROM DUAL; round ------- 3 (1 row) openGauss=# SELECT TRUNC(3.14) FROM DUAL; trunc ------- 3 (1 row)	SQL> SELECT ROUND(3.14) FROM DUAL; ROUND(3.14) ----------- 3 SQL> SELECT TRUNC(3.14) FROM DUAL; TRUNC(3.14) ----------- 3	支持
28	`SIGN`	SELECT SIGN(-10) FROM DUAL;	openGauss=# SELECT SIGN(-10) FROM DUAL; sign ------ -1 (1 row)	SQL> SELECT SIGN(-10) FROM DUAL; SIGN(-10) ---------- -1	支持
29	`SIN`	SELECT SIN(0) FROM DUAL;	openGauss=# SELECT SIN(0) FROM DUAL; sin ----- 0 (1 row)	SQL> SELECT SIN(0) FROM DUAL; SIN(0) ---------- 0	支持
30	`SINH`	SELECT SINH(0) FROM DUAL;	openGauss=# SELECT SINH(0) FROM DUAL; ERROR: function sinh(integer) does not exist LINE 1: SELECT SINH(0) FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: sinh openGauss=#	SQL> SELECT SINH(0) FROM DUAL; SINH(0) ---------- 0	不支持
31	`SQRT`	SELECT SQRT(16) FROM DUAL;	openGauss=# SELECT SQRT(16) FROM DUAL; sqrt ------ 4 (1 row)	SQL> SELECT SQRT(16) FROM DUAL; SQRT(16) ---------- 4	支持
32	`TAN`	SELECT TAN(0) FROM DUAL;	openGauss=# SELECT TAN(0) FROM DUAL; tan ----- 0 (1 row)	SQL> SELECT TAN(0) FROM DUAL; TAN(0) ---------- 0	支持
33	`TANH`	SELECT TANH(0) FROM DUAL;	openGauss=# SELECT TANH(0) FROM DUAL; ERROR: function tanh(integer) does not exist LINE 1: SELECT TANH(0) FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: tanh	SQL> SELECT TANH(0) FROM DUAL; TANH(0) ---------- 0	不支持
34	`TRUNC`	SELECT TRUNC(3.14) FROM DUAL;	openGauss=# SELECT TRUNC(3.14) FROM DUAL; trunc ------- 3 (1 row)	SQL> SELECT TRUNC(3.14) FROM DUAL; 3	支持
35	`ADD_MONTHS`	SELECT ADD_MONTHS(SYSDATE, 1) FROM DUAL;	openGauss=# SELECT ADD_MONTHS(SYSDATE, 1) FROM DUAL; add_months --------------------- 2023-09-05 21:02:13 (1 row)	SQL> SELECT ADD_MONTHS(SYSDATE, 1) FROM DUAL; 2023:09:0521:02:12	支持
36	`LAST_DAY`	SELECT LAST_DAY(SYSDATE) FROM DUAL;	openGauss=# SELECT LAST_DAY(SYSDATE) FROM DUAL; last_day --------------------- 2023-08-31 21:03:52 (1 row)	SQL> SELECT LAST_DAY(SYSDATE) FROM DUAL; 2023:08:3121:03:51	支持
37	`MONTHS_BETWEEN`	SELECT MONTHS_BETWEEN(TO_DATE('2022-07-01', 'YYYY-MM-DD'), TO_DATE('2022-01-01', 'YYYY-MM-DD')) FROM DUAL;	openGauss=# SELECT MONTHS_BETWEEN(TO_DATE('2022-07-01', 'YYYY-MM-DD'), TO_DATE('2022-01-01', 'YYYY-MM-DD')) FROM DUAL; ERROR: function months_between(timestamp without time zone, timestamp without time zone) does not exist LINE 1: SELECT MONTHS_BETWEEN(TO_DATE('2022-07-01', 'YYYY-MM-DD'), T... ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: months_between	SQL> SELECT MONTHS_BETWEEN(TO_DATE('2022-07-01', 'YYYY-MM-DD'), TO_DATE('2022-01-01', 'YYYY-MM-DD')) FROM DUAL; 6	不支持
38	`NEW_TIME`	SELECT NEW_TIME(SYSDATE, 'EST', 'PST') FROM DUAL;	openGauss=# SELECT NEW_TIME(SYSDATE, 'EST', 'PST') FROM DUAL; ERROR: function new_time(timestamp without time zone, unknown, unknown) does not exist LINE 1: SELECT NEW_TIME(SYSDATE, 'EST', 'PST') FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: new_time	SQL> SELECT NEW_TIME(SYSDATE, 'EST', 'PST') FROM DUAL; 2023:08:0518:05:28	不支持
39	`NEXT_DAY`	SELECT NEXT_DAY(SYSDATE, 'SUNDAY') FROM DUAL;	openGauss=# SELECT NEXT_DAY(SYSDATE, 'SUNDAY') FROM DUAL; next_day --------------------- 2023-08-06 21:06:25 (1 row)	SQL> SELECT NEXT_DAY(SYSDATE, 'SUNDAY') FROM DUAL; 2023:08:0621:06:24	支持
40	`SYSDATE`	SELECT SYSDATE FROM DUAL;	openGauss=# SELECT SYSDATE FROM DUAL; sysdate --------------------- 2023-08-05 21:07:08 (1 row)	SQL> SELECT SYSDATE FROM DUAL; 2023:08:0521:07:08	支持
41	`CHARTOROWID`	SELECT CHARTOROWID('AAAVmKAABAAAXFRAAA') from dual;	openGauss=# SELECT CHARTOROWID('AAAVmKAABAAAXFRAAA') from dual; ERROR: function chartorowid(unknown) does not exist LINE 1: SELECT CHARTOROWID('AAAVmKAABAAAXFRAAA') from dual; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: chartorowid	SQL> SELECT CHARTOROWID('AAAVmKAABAAAXFRAAA') from dual; AAAVmKAABAAAXFRAAA	不支持
42	`CONVERT`	SELECT CONVERT('Hello', 'WE8ISO8859P1', 'US7ASCII') FROM DUAL;	openGauss=# SELECT CONVERT('Hello', 'WE8ISO8859P1', 'US7ASCII') FROM DUAL; ERROR: invalid source encoding name "WE8ISO8859P1" CONTEXT: referenced column: convert	SQL> SELECT CONVERT('Hello', 'WE8ISO8859P1', 'US7ASCII') FROM DUAL; Hello	不支持
43	`HEXTORAW`	SELECT HEXTORAW('414243') FROM DUAL;	openGauss=# SELECT HEXTORAW('414243') FROM DUAL; hextoraw ---------- 414243 (1 row)	SQL> SELECT HEXTORAW('414243') FROM DUAL; 414243	支持
44	`RAWTOHEX`	SELECT RAWTOHEX('ABC') FROM DUAL;	openGauss=# SELECT RAWTOHEX('ABC') FROM DUAL; rawtohex ---------- 414243 (1 row)	SQL> SELECT RAWTOHEX('ABC') FROM DUAL; 414243	支持
45	`ROWIDTOCHAR`	SELECT ROWIDTOCHAR('AAAVmKAABAAAXFRAAA') FROM DUAL;	openGauss=# SELECT ROWIDTOCHAR('AAAVmKAABAAAXFRAAA') FROM DUAL; ERROR: function rowidtochar(unknown) does not exist LINE 1: SELECT ROWIDTOCHAR('AAAVmKAABAAAXFRAAA') FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: rowidtochar	SQL> SELECT ROWIDTOCHAR('AAAVmKAABAAAXFRAAA') FROM DUAL; AAAVmKAABAAAXFRAAA	不支持
46	`TO_CHAR`	SELECT TO_CHAR(12345) AS converted_value FROM DUAL;	openGauss=# SELECT TO_CHAR(12345) AS converted_value FROM DUAL; converted_value ----------------- 12345 (1 row)	SQL> SELECT TO_CHAR(12345) AS converted_value FROM DUAL; 12345	支持
47	`TO_DATE`	SELECT TO_DATE('2022-07-01', 'YYYY-MM-DD') FROM DUAL;	openGauss=# SELECT TO_DATE('2022-07-01', 'YYYY-MM-DD') FROM DUAL; to_date --------------------- 2022-07-01 00:00:00 (1 row)	SQL> SELECT TO_DATE('2022-07-01', 'YYYY-MM-DD') FROM DUAL; 2022:07:0100:00:00	支持
48	`TO_MULTI_BYTE`	SELECT TO_MULTI_BYTE('Hello') FROM DUAL;	openGauss=# SELECT TO_MULTI_BYTE('Hello') FROM DUAL; ERROR: function to_multi_byte(unknown) does not exist LINE 1: SELECT TO_MULTI_BYTE('Hello') FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: to_multi_byte	SQL> SELECT TO_MULTI_BYTE('Hello') FROM DUAL; Ｈｅｌｌｏ	不支持
49	`TO_NUMBER`	SELECT TO_NUMBER('123.45', '999.99') FROM DUAL;	openGauss=# SELECT TO_NUMBER('123.45', '999.99') FROM DUAL; to_number ----------- 123.45 (1 row)	SQL> SELECT TO_NUMBER('123.45', '999.99') FROM DUAL; 123.45	支持
50	`BFILENAME`	SELECT BFILENAME('DIRECTORY', 'filename.jpg') AS file_name FROM DUAL;	openGauss=# SELECT BFILENAME('DIRECTORY', 'filename.jpg') AS file_name FROM DUAL; ERROR: function bfilename(unknown, unknown) does not exist LINE 1: SELECT BFILENAME('DIRECTORY', 'filename.jpg') AS file_name F... ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: file_name	SQL> SELECT BFILENAME('DIRECTORY', 'filename.jpg') AS file_name FROM DUAL; bfilename('DIRECTORY', 'filename.jpg')	不支持
51	`DUMP`	SELECT DUMP('Hello') FROM DUAL;	openGauss=# SELECT DUMP('Hello') FROM DUAL; ERROR: function dump(unknown) does not exist LINE 1: SELECT DUMP('Hello') FROM DUAL; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: dump	SQL> SELECT DUMP('Hello') FROM DUAL; Typ=96 Len=5: 72,101,108,108,111	不支持
52	`GREATEST`	SELECT GREATEST(2, 5, 3) FROM DUAL;	openGauss=# SELECT GREATEST(2, 5, 3) FROM DUAL; greatest ---------- 5 (1 row)	SQL> SELECT GREATEST(2, 5, 3) FROM DUAL; 5	支持
53	`LEAST`	SELECT LEAST(2, 5, 3) FROM DUAL;	openGauss=# SELECT LEAST(2, 5, 3) FROM DUAL; least ------- 2 (1 row)	SQL> SELECT LEAST(2, 5, 3) FROM DUAL; 2	支持
54	`UID`	SELECT UID FROM DUAL;	openGauss=# SELECT UID FROM DUAL; ERROR: column "uid" does not exist LINE 1: SELECT UID FROM DUAL; ^ CONTEXT: referenced column: uid	SQL> SELECT UID FROM DUAL; 0	不支持
55	`USER`	SELECT USER FROM DUAL;	openGauss=# SELECT USER FROM DUAL; current_user -------------- omm (1 row)	SQL> SELECT USER FROM DUAL; SYS	支持
56	`AVG`	SELECT AVG(salary) FROM employees;	openGauss=# SELECT AVG(salary) FROM employees; avg -------------------- 65000.000000000000 (1 row)	SQL> SELECT AVG(salary) FROM employees; 65000	支持
57	`MAX`	SELECT MAX(salary) FROM employees;	openGauss=# SELECT MAX(salary) FROM employees; max ------- 65000 (1 row)	SQL> SELECT MAX(salary) FROM employees; 65000	支持
58	`MIN`	SELECT MIN(salary) FROM employees;	openGauss=# SELECT MIN(salary) FROM employees; min ------- 65000 (1 row)	SQL> SELECT MIN(salary) FROM employees; 65000	支持
59	`STDDEV`	SELECT STDDEV(salary) FROM employees;	openGauss=# SELECT STDDEV(salary) FROM employees; stddev -------- (1 row)	SQL> SELECT STDDEV(salary) FROM employees; 0	支持
60	`VARIANCE`	SELECT VARIANCE(salary) FROM employees;	openGauss=# SELECT VARIANCE(salary) FROM employees; variance ---------- (1 row)	SQL> SELECT VARIANCE(salary) FROM employees; 0	支持
61	`GROUP BY`	SELECT department_id, AVG(salary) FROM employees GROUP BY department_id;	openGauss=# openGauss=# SELECT department_id, AVG(salary) FROM employees GROUP BY department_id; department_id \| avg ---------------+-------------------- 60 \| 65000.000000000000 (1 row)	SQL> SELECT department_id, AVG(salary) FROM employees GROUP BY department_id; 60 65000	支持
62	`HAVING`	SELECT department_id, AVG(salary) FROM employees GROUP BY department_id HAVING AVG(salary) > 5000;	openGauss=# SELECT department_id, AVG(salary) FROM employees GROUP BY department_id HAVING AVG(salary) > 5000; department_id \| avg ---------------+-------------------- 60 \| 65000.000000000000 (1 row)	SQL> SELECT department_id, AVG(salary) FROM employees GROUP BY department_id HAVING AVG(salary) > 5000; 60 65000	支持
63	`ORDER BY`	SELECT * FROM employees ORDER BY salary DESC;	openGauss=# SELECT * FROM employees ORDER BY salary DESC; employee_id \| first_name \| last_name \| email \| phone_number \| hire_date \| job_id \| salary \| commission_pct \| ma nager_id \| department_id -------------+------------+-----------+----------------------+--------------+---------------------+---------+--------+----------------+--- ---------+--------------- 101 \| John \| Doe \| john.doe@example.com \| 123-456-7890 \| 2023-01-15 00:00:00 \| IT_PROG \| 65000 \| \| \| 60 (1 row)	SQL> SELECT * FROM employees ORDER BY salary DESC; 101 John Doe john.doe@example.com 123-456-7890 2023:01:1500:00:00 IT_PROG 65000 60	支持
64	`CASE statement in PL/SQL`	DECLARE salary NUMBER := 5000; BEGIN CASE WHEN salary > 10000 THEN DBMS_OUTPUT.PUT_LINE ('High Salary'); WHEN salary > 5000 THEN DBMS_OUTPUT.PUT_LINE ('Medium Salary'); ELSE DBMS_OUTPUT.PUT_LINE ('Low Salary'); END CASE; END; /	openGauss=# DECLARE salary NUMBER := 5000; openGauss-# openGauss-# BEGIN CASE WHEN salary > 10000 THEN DBMS_OUTPUT.PUT_LINE ('High Salary'); openGauss$# openGauss$# openGauss$# openGauss$# openGauss$# WHEN salary > 5000 openGauss$# THEN openGauss$# DBMS_OUTPUT.PUT_LINE ('Medium Salary'); openGauss$# ELSE openGauss$# DBMS_OUTPUT.PUT_LINE ('Low Salary'); openGauss$# END CASE; openGauss$# END; openGauss$# / ERROR: schema "dbms_output" does not exist CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1	SQL> DECLARE 2 salary NUMBER := 5000; 3 BEGIN 4 CASE WHEN salary > 10000 5 6 THEN DBMS_OUTPUT.PUT_LINE ('High Salary'); 7 8 WHEN salary > 5000 9 THEN DBMS_OUTPUT.PUT_LINE ('Medium Salary'); 10 11 ELSE 12 DBMS_OUTPUT.PUT_LINE ('Low Salary'); END CASE; 13 14 END; 15 / PL/SQL procedure successfully completed.	不支持
65	`NVL`	SELECT NVL(FIRST_NAME,LAST_NAME) from employees;	openGauss=# SELECT NVL(FIRST_NAME,LAST_NAME) from employees; nvl ------ John (1 row)	SQL> SELECT NVL(FIRST_NAME,LAST_NAME) from employees; John	支持
67	`AVG`	SELECT AVG(salary) FROM employees;	openGauss=# SELECT AVG(salary) FROM employees; avg -------------------- 65000.000000000000 (1 row)	SQL> SELECT AVG(salary) FROM employees; 65000	支持
68	`COUNT`	SELECT COUNT(salary) FROM employees;	openGauss=# SELECT COUNT(salary) FROM employees; count ------- 1 (1 row)	SQL> SELECT COUNT(salary) FROM employees; 1	支持
69	`FIRST_VALUE`	SELECT FIRST_VALUE(salary) OVER (PARTITION BY EMPLOYEE_ID ORDER BY DEPARTMENT_ID) FROM employees;	openGauss=# SELECT FIRST_VALUE(salary) OVER (PARTITION BY EMPLOYEE_ID ORDER BY DEPARTMENT_ID) FROM employees; first_value ------------- 65000 (1 row)	SQL> SELECT FIRST_VALUE(salary) OVER (PARTITION BY EMPLOYEE_ID ORDER BY DEPARTMENT_ID) FROM employees; 65000	支持
70	`LAG`	SELECT LAG(salary) OVER (ORDER BY DEPARTMENT_ID) FROM employees;	openGauss=# SELECT LAG(salary) OVER (ORDER BY DEPARTMENT_ID) FROM employees; lag ----- (1 row)	SQL> SELECT LAG(salary) OVER (ORDER BY DEPARTMENT_ID) FROM employees; SQL>	支持
71	`LAST_VALUE`	SELECT LAST_VALUE(salary) OVER (PARTITION BY EMPLOYEE_ID ORDER BY DEPARTMENT_ID) FROM employees;	openGauss=# SELECT LAST_VALUE(salary) OVER (PARTITION BY EMPLOYEE_ID ORDER BY DEPARTMENT_ID) FROM employees; last_value ------------ 65000 (1 row)	SQL> SELECT LAST_VALUE(salary) OVER (PARTITION BY EMPLOYEE_ID ORDER BY DEPARTMENT_ID) FROM employees; 65000	支持
72	`LEAD`	SELECT LEAD(salary) OVER (ORDER BY EMPLOYEE_ID) FROM employees;	openGauss=# SELECT LEAD(salary) OVER (ORDER BY EMPLOYEE_ID) FROM employees; lead ------ (1 row)	SQL> SELECT LEAD(salary) OVER (ORDER BY EMPLOYEE_ID) FROM employees; SQL>	支持
73	`ROW_NUMBER`	SELECT ROW_NUMBER() OVER (ORDER BY salary) FROM employees;	openGauss=# SELECT ROW_NUMBER() OVER (ORDER BY salary) FROM employees; row_number ------------ 1 (1 row)	SQL> SELECT ROW_NUMBER() OVER (ORDER BY salary) FROM employees; 1	支持
74	`STDDEV`	SELECT STDDEV(salary) FROM employees;	openGauss=# SELECT STDDEV(salary) FROM employees; stddev -------- (1 row) openGauss=#	SQL> SELECT STDDEV(salary) FROM employees; 0	支持
75	`STDDEV_POP`	SELECT STDDEV_POP(salary) FROM employees;	openGauss=# SELECT STDDEV_POP(salary) FROM employees; stddev_pop ------------ 0 (1 row) openGauss=#	SQL> SELECT STDDEV_POP(salary) FROM employees; 0	支持
76	`STDDEV_SAMP`	SELECT STDDEV_SAMP(salary) FROM employees;	openGauss=# SELECT STDDEV_SAMP(salary) FROM employees; stddev_samp ------------- (1 row) openGauss=#	SQL> SELECT STDDEV_SAMP(salary) FROM employees; SQL>	支持
77	`SUM (Aggregate Function)`	SELECT SUM(salary) FROM employees;	openGauss=# SELECT SUM(salary) FROM employees; sum ------- 65000 (1 row) openGauss=#	SQL> SELECT SUM(salary) FROM employees; 65000	支持
78	`VAR_POP (Aggregate Function)`	SELECT VAR_POP(salary) FROM employees;	openGauss=# SELECT VAR_POP(salary) FROM employees; var_pop --------- 0 (1 row)	SQL> SELECT VAR_POP(salary) FROM employees; 0 SQL>	支持
79	`VAR_SAMP (Aggregate Function)`	SELECT VAR_SAMP(salary) FROM employees;	openGauss=# SELECT VAR_SAMP(salary) FROM employees; var_samp ---------- (1 row)	SQL> SELECT VAR_SAMP(salary) FROM employees; SQL>	支持
80	`VARIANCE (Aggregate Function)`	SELECT VARIANCE(salary) FROM employees;	openGauss=# SELECT VARIANCE(salary) FROM employees; variance ---------- (1 row) openGauss=#	SQL> SELECT VARIANCE(salary) FROM employees; 0	支持
81	`RANK (Aggregate Function)`	SELECT RANK() OVER (ORDER BY salary) FROM employees;	openGauss=# SELECT RANK() OVER (ORDER BY salary) FROM employees; rank ------ 1 (1 row) openGauss=#	SQL> SELECT RANK() OVER (ORDER BY salary) FROM employees; 1 SQL>	支持
82	`RATIO_TO_REPORT (Aggregate Function)`	SELECT RATIO_TO_REPORT(salary) OVER () FROM employees;	openGauss=# SELECT RATIO_TO_REPORT(salary) OVER () FROM employees; ERROR: function ratio_to_report(numeric) does not exist LINE 1: SELECT RATIO_TO_REPORT(salary) OVER () FROM employees; ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. CONTEXT: referenced column: ratio_to_report	SQL> SELECT RATIO_TO_REPORT(salary) OVER () FROM employees; 1 SQL>	不支持
83	`ROW_NUMBER (Aggregate Function)`	SELECT ROW_NUMBER() OVER (ORDER BY salary) FROM employees;	openGauss=# SELECT ROW_NUMBER() OVER (ORDER BY salary) FROM employees; row_number ------------ 1 (1 row) openGauss=#	SQL> SELECT ROW_NUMBER() OVER (ORDER BY salary) FROM employees; 1 SQL>	支持
84	`STDDEV (Aggregate Function)`	SELECT STDDEV(salary) FROM employees;	openGauss=# SELECT STDDEV(salary) FROM employees; stddev -------- (1 row)	SQL> SELECT STDDEV(salary) FROM employees; 0	支持
85	`STDDEV_POP (Aggregate Function)`	SELECT STDDEV_POP(salary) FROM employees;	openGauss=# SELECT STDDEV_POP(salary) FROM employees; stddev_pop ------------ 0 (1 row)	SQL> SELECT STDDEV_POP(salary) FROM employees; 0	支持
86	`STDDEV_SAMP (Aggregate Function)`	SELECT STDDEV_SAMP(salary) FROM employees;	openGauss=# SELECT STDDEV_SAMP(salary) FROM employees; stddev_samp ------------- (1 row)	SQL> SELECT STDDEV_SAMP(salary) FROM employees; SQL>	支持
87	`SUM (Aggregate Function)`	SELECT sum(salary) FROM employees;	openGauss=# SELECT sum(salary) FROM employees; sum ------- 65000 (1 row)	SQL> SELECT sum(salary) FROM employees; 65000	支持
88	`VAR_POP (Aggregate Function)`	SELECT VAR_POP(salary) FROM employees;	openGauss=# SELECT VAR_POP(salary) FROM employees; var_pop --------- 0 (1 row) openGauss=#	SQL> SELECT VAR_POP(salary) FROM employees; 0	支持
89	`VAR_SAMP (Aggregate Function)`	SELECT VAR_SAMP(salary) FROM employees;	openGauss=# SELECT VAR_SAMP(salary) FROM employees; var_samp ---------- (1 row) openGauss=#	SQL> SELECT VAR_SAMP(salary) FROM employees; SQL>	支持
90	`VARIANCE (Aggregate Function)`	SELECT VARIANCE(salary) FROM employees;	openGauss=# SELECT VARIANCE(salary) FROM employees; variance ---------- (1 row) openGauss=#	SQL> SELECT VARIANCE(salary) FROM employees; 0 SQL>	支持