流批一体数据交换 etl-engine 融合查询语法

原创

威哥

发布于 2023-06-04 15:22:52

3710

发布于 2023-06-04 15:22:52

文章被收录于专栏：etl

融合查询语法

etl-engine引擎中的融合查询提供将多源数据在内存中重组关联查询并输出查询结果的能力。

融合查询语法遵循ANSI SQL标准，与常规MySQL查询语法很相似。

支持对多种类别数据库之间读取的数据进行融合查询。
支持消息流数据传输过程中动态产生的数据与多种类型数据库之间的流计算查询。
融合查询语法遵循ANSI SQL标准。

样本

SELECT 
	t_u.u_id,t_u.u_name,t_u.u_phone,
	t_o.o_id,t_o.o_price,t_o.o_number,t_o.o_money,t_o.o_writetime,
	t_p.p_id,t_p.p_name,t_p.p_contacts,t_p.p_desc  
FROM  t_u 
	inner JOIN  t_o  
	ON t_o.u_id=t_u.u_id 
	inner JOIN  t_p 
	ON t_o.p_id=t_p.p_id 
ORDER BY  
	INTEGER(SUBSTRING(t_u.u_id,3))  ASC

语法格式

select 支持

SELECT
      [DISTINCT] field [, field ...]
      FROM table [, table ...]
      [WHERE condition]
      [GROUP BY field [, field ...] ]
      [HAVING condition]
   [ORDER BY order_item [, order_item ...] ]
   [LIMIT number_of_records [OFFSET number_of_records ] ]

table 支持 INNER JOIN、LEFT JOIN、RIGHT JOIN、OUTER JOIN、CROSS JOIN等

运算符支持

+ - * / == < <= > >= <> != || IS BETWEEN IN LIKE NOT ANY AND OR INTERSECT UNION EXCEPT EXISTS

函数支持

逻辑函数

COALESCE(value [, value ...])
IF(condition, value1, value2)
IFNULL(value1, value2)
NULLIF(value1, value2)

数字函数（30多个）

ABS(number)
ACOS(number)
ACOSH(number)
ASIN(number)
ASINH(number)
ATAN(number)
ATAN2(number2, number1)
ATANH(number)
CBRT(number)
CEIL(number)
COS(number)
COSH(number)
EXP(number)
EXP2(number)
EXPM1(number)
FLOOR(number)
IS_INF(number [, sign])
IS_NAN(number)
LOG(number)
LOG10(number)
LOG1P(number)
LOG2(number)
LOGB(number)
POW(base, exponent)
ROUND(number)
SIN(number)
SINH(number)
SQRT(number)
TAN(number)
TANH(number)
BIN_TO_DEC(bin)
OCT_TO_DEC(oct)
HEX_TO_DEC(hex)
ENOTATION_TO_DEC(enotation)
BIN(integer)
OCT(integer)
HEX(integer)
ENOTATION(float)
NUMBER_FORMAT(number [, precision, decimalPoint, thousandsSeparator, decimalSeparator])
RAND(min, max)

日期函数（30多个）

NOW()
DATETIME_FORMAT(datetime, format)
YEAR(datetime)
MONTH(datetime)
DAY(datetime)
HOUR(datetime)
MINUTE(datetime)
SECOND(datetime)
MILLISECOND(datetime)
MICROSECOND(datetime)
NANOSECOND(datetime)
WEEKDAY(datetime)
UNIX_TIME(datetime)
UNIX_NANO_TIME(datetime)
DAY_OF_YEAR(datetime)
WEEK_OF_YEAR(datetime)
ADD_YEAR(datetime, duration)
ADD_MONTH(datetime, duration)
ADD_DAY(datetime, duration)
ADD_HOUR(datetime, duration)
ADD_MINUTE(datetime, duration)
ADD_SECOND(datetime, duration)
ADD_MILLI(datetime, duration)
ADD_MICRO(datetime, duration)
ADD_NANO(datetime, duration)
TRUNC_MONTH(datetime)
TRUNC_DAY(datetime)
TRUNC_TIME(datetime)
TRUNC_MINUTE(datetime)
TRUNC_SECOND(datetime)
TRUNC_MILLI(datetime)
TRUNC_MICRO(datetime)
TRUNC_NANO(datetime)
DATE_DIFF(datetime1, datetime2)
TIME_DIFF(datetime1, datetime2)
TIME_NANO_DIFF(datetime1, datetime2)
UTC(datetime)
MILLI_TO_DATETIME(unix_milliseconds)
NANO_TO_DATETIME(unix_nano_time)

字符串函数（20多个）

TRIM(str)
LTRIM(str)
RTRIM(str)
UPPER(str)
LOWER(str)
BASE64_ENCODE(str)
BASE64_DECODE(str)
HEX_ENCODE(str)
HEX_DECODE(str)
LEN(str)
SUBSTRING(str, position [, len])
SUBSTR(str, position [, len])
INSTR(str, substr)
LIST_ELEM(str, sep, index)
REPLACE(str, old, new)
REGEXP_MATCH(str, regexp [, flags])
REGEXP_FIND(str, regexp [, flags])
TITLE_CASE(str)

加密函数

MD5(str) 	
SHA1(str) 	
SHA256(str) 	
SHA512(str) 	
MD5_HMAC(str,key_str) 	
SHA1_HMAC(str,key_str)  
SHA256_HMAC(str,key_str)  	
SHA512_HMAC(str,key_str)

类型转换函数

STRING(value)
INTEGER(value)
FLOAT(value)
DATETIME(value [, timezone])
BOOLEAN(value)

聚合函数

COUNT([DISTINCT] *)
MIN(expr)
MAX(expr)
SUM([DISTINCT] expr)
AVG([DISTINCT] expr)

参考资料

  etl-engine使用手册(https://github.com/hw2499/etl-engine)
  etl-crontab使用手册(https://github.com/hw2499/etl-engine/wiki/etl-crontab%E8%B0%83%E5%BA%A6)
  嵌入脚本开发(https://github.com/hw2499/etl-engine/wiki/%E5%B5%8C%E5%85%A5%E8%84%9A%E6%9C%AC%E5%BC%80%E5%8F%91)
  etl-engine配置样例(https://github.com/hw2499/etl-engine/wiki/etl-engine%E4%BD%BF%E7%94%A8%E6%A0%B7%E4%BE%8B)

原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。

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