SAPHANA学习（10）：SQL Function(I)

75.IFNULL

IFNULL(<expression1>, <expression2>)

返回第一个非空表达式

*/

SELECT IFNULL('diff', 'same') FROM DUMMY;
SELECT IFNULL(NULL, 'same') FROM DUMMY;
SELECT IFNULL(NULL, NULL) FROM DUMMY;

/*

76.INDEXING_ERROR_CODE

INDEXING_ERROR_CODE(<column_name>)

返回具有全文索引列的值的错误代码

INDEXING_ERROR_MESSAGE(<column_name>)

返回具有全文索引列值的错误信息

INDEXING_STATUS(<column_name>)

Status值说明：

ERROR - the value could not be indexed due to a mismatch in the data type

INDEXED - the value is been indexed

QUEUED - the value is queued for indexing

*/

CREATE COLUMN TABLE TEST_INDEX_ERROR_CODE (CONTENT varchar(50));
CREATE FULLTEXT INDEX I ON TEST_INDEX_ERROR_CODE(CONTENT) ASYNC MIME TYPE 'text/xml' FAST PREPROCESS OFF;
INSERT INTO TEST_INDEX_ERROR_CODE VALUES ('This is an example');
INSERT INTO TEST_INDEX_ERROR_CODE VALUES ('<xml>This is an example</xml>'); –- Wait a few seconds

SELECT INDEXING_ERROR_CODE(CONTENT),CONTENT FROM TEST_INDEX_ERROR_CODE;
SELECT INDEXING_ERROR_MESSAGE(CONTENT),CONTENT FROM TEST_INDEX_ERROR_CODE;
SELECT INDEXING_STATUS(CONTENT),CONTENT FROM TEST_INDEX_ERROR_CODE;

--QUEUED 排序
ALTER FULLTEXT INDEX I SUSPEND QUEUE;
INSERT INTO TEST_INDEX_ERROR_CODE VALUES ('<xml>its INDEXING_STATUS is QUEUED</xm>');
SELECT INDEXING_STATUS(CONTENT),CONTENT FROM TEST_INDEX_ERROR_CODE;

/*

77.INITCAP

INITCAP(<inputString>)

将字符串首字母大写，其余小写

<inputString> can be either a VARCHAR or NVARCHAR value.

*/

--不存在??
--SELECT INITCAP('the EXAMPLE one') FROM DUMMY;

/*

78.IS_SQL_INJECTION_SAFE(<value>[, <max_tokens>])

检查SQL是否存在注入风险

<max_tokens>：最大风险字符个数，如果超过返回0（not safe）,没有超过返回1

这些是风险字符

空格 , ( ) [ ] . ; : + - * / % ^ < >  =

*/

SELECT IS_SQL_INJECTION_SAFE('tab,le') FROM DUMMY;
SELECT IS_SQL_INJECTION_SAFE('CREATE STRUCTURED PRIVILEGE', 3) FROM DUMMY;
--存在注释/*不安全
SELECT IS_SQL_INJECTION_SAFE('mytab /*', 4) FROM DUMMY;

/*

79.ISOWEEK

ISOWEEK(<date>)

返回ISO年，周信息<date>

week数字前有W字母

*/

SELECT ISOWEEK(TO_DATE('2011-05-30', 'YYYY-MM-DD')) FROM DUMMY;