SQL 快速参考

Apache Kylin 使用 Apache Calcite 做 SQL 解析和优化。作为一款 OLAP 引擎, Kylin 支持 SELECT 操作，而不支持其它操作例如 INSERT，UPDATE 和 DELETE，因此 Kylin 的 SQL 语法是 Apache Calcite 支持语法的一个子集。本文列举了 Kylin 支持的 SQL 语法、函数以及数据类型，但可能并不完整。您可以查看 Calcite SQL reference 以了解更多内容。

语法

QUERY SYNTAX
SELECT
　STATEMENT
　EXPRESSION
SUBQUERY
JOIN
　INNER JOIN
　LEFT JOIN
UNION
UNION ALL

函数

COUNT
　COUNT(COLUMN)
　COUNT(*)
COUNT_DISTINCT
MAX
MIN
PERCENTILE
SUM
TOP_N

WINDOW
　ROW_NUMBER
　AVG
　RANK
　DENSE_RANK
　FIRST_VALUE
　LAST_VALUE
　LAG
　LEAD
　NTILE
　CASE WHEN
　CAST

SUSTRING
COALESCE

数据类型

数据类型

查询语法

  1. statement:
  2. |  query
  4. query:
  5.       values
  6.   |  WITH withItem [ , withItem ]* query
  7.   |   {
  8.           select
  9.       |  selectWithoutFrom
  10.       |  query UNION [ ALL | DISTINCT ] query
  11.       |  query INTERSECT [ ALL | DISTINCT ] query
  12.       }
  13.       [ ORDER BY orderItem [, orderItem ]* ]
  14.       [ LIMIT { count | ALL } ]
  15.       [ OFFSET start { ROW | ROWS } ]
  16.       [ FETCH { FIRST | NEXT } [ count ] { ROW| ROWS } ]
  18. withItem:
  19.       name
  20.       ['(' column [, column ]* ')' ]
  21.       AS '(' query ')'
  23. orderItem:
  24.       expression [ ASC | DESC ]［ NULLS FIRST |NULLS LAST ］
  26. select:
  27.       SELECT [ ALL | DISTINCT]
  28.           { * | projectItem [, projectItem ]* }
  29.       FROM tableExpression
  30.       [ WHERE booleanExpression ]
  31.       [ GROUP BY { groupItem [, groupItem ]* }]
  32.       [ HAVING booleanExpression ]
  33.       [ WINDOW windowName AS windowSpec [,windowName AS windowSpec ]* ]
  35. selectWithoutFrom:
  36.       SELECT [ ALL | DISTINCT ]
  37.           { * | projectItem [, projectItem ]* }
  39. projectItem:
  40.       expression [ [ AS ] columnAlias ]
  41.   |  tableAlias . *
  43. tableExpression:
  44.       tableReference [, tableReference ]*
  45.   |  tableExpression [ NATURAL ]［( LEFT | RIGHT | FULL ) [ OUTER ] ］ JOIN tableExpression [ joinCondition ]
  47. joinCondition:
  48.       ON booleanExpression
  49.   |  USING '(' column [, column ]* ')'
  51. tableReference:
  52.       tablePrimary
  53.       [ matchRecognize ]
  54.       [ [ AS ] alias [ '(' columnAlias [,columnAlias ]* ')' ] ]
  56. tablePrimary:
  57.       [ [ catalogName . ] schemaName . ] tableName
  58.       '(' TABLE [ [ catalogName . ] schemaName. ] tableName ')'
  59.   |   [ LATERAL ] '(' query ')'
  60.   |  UNNEST '(' expression ')' [ WITH ORDINALITY ]
  61.   |   [ LATERAL ] TABLE '(' [ SPECIFIC ] functionName '(' expression [, expression ]*')' ')'
  63. values:
  64.       VALUES expression [, expression ]*
  66. groupItem:
  67.       expression
  68.   |   '('')'
  69.   |   '('expression [, expression ]* ')'
  70.   |  GROUPING SETS '(' groupItem [, groupItem ]* ')'
  72. windowRef:
  73.       windowName
  74.   |  windowSpec
  76. windowSpec:
  77.       [windowName ]
  78.       '('
  79.       [ ORDER BY orderItem [, orderItem ]* ]
  80.       [ PARTITION BY expression [, expression]* ]
  81.       [
  82.           RANGE numericOrIntervalExpression { PRECEDING | FOLLOWING }
  83.       |  ROWS numericExpression { PRECEDING | FOLLOWING }
  84.       ]
  85.     ')'

SELECT

STATEMENT

SELECT 用于从表中选取数据。COUNT 用于统计数据。DISTINCT 过滤掉重复的结果。AS 用于给表或列起别名。FROM 指定要查询的表。JOIN 用于连接两个表以获取所需的数据。WHERE 用于规定选择的标准。LIKE 用于在 WHERE 子句中搜索列中的指定模式。BETWEEN ... AND 选取介于两个值之间的数据范围。AND 和 OR 用于基于一个以上的条件对记录进行过滤。GROUP BY 按给定表达式对结果进行分组。HAVING 用于分组后过滤行。ORDER BY 用于对结果集进行排序，通常和 TOPN 一起使用。LIMIT 用来限制查询返回的行数。

例子：

  1. SELECT COUNT(*) FROM kylin_sales;
  3. SELECT COUNT(DISTINCT seller_id) FROM kylin_sales;
  5. SELECT seller_id, COUNT(1) FROM kylin_sales GROUP BY seller_id;
  7. SELECT lstg_format_name, SUM(price) AS gmv, COUNT(DISTINCT seller_id) AS dist_seller FROM kylin_sales WHERE lstg_format_name='FP-GTC' GROUP BY lstg_format_name HAVING COUNT(DISTINCT seller_id) > 50;
  9. SELECT lstg_format_name FROM kylin_sales INNER JOIN kylin_cal_dt AS kylin_cal_dt ON kylin_sales.part_dt = kylin_cal_dt.cal_dt WHERE NOT(lstg_format_name NOT LIKE '%ab%') GROUP BY lstg_format_name;
  11. SELECT kylin_cal_dt.cal_dt FROM kylin_sales INNER JOIN kylin_cal_dt AS kylin_cal_dt ON kylin_sales.part_dt = kylin_cal_dt.cal_dt WHERE kylin_cal_dt.cal_dt BETWEEN DATE '2013-01-01' AND DATE '2013-06-04';
  13. SELECT kylin_sales.lstg_format_name, SUM(kylin_sales.price) AS gmv, COUNT(*) AS trans_cnt FROM kylin_sales WHERE kylin_sales.lstg_format_name IS NULL GROUP BY kylin_sales.lstg_format_name HAVING SUM(price)>5000 AND COUNT(*)>72; 
  15. SELECT kylin_sales.lstg_format_name, SUM(kylin_sales.price) AS gmv, COUNT(*) AS trans_cnt FROM kylin_sales WHERE kylin_sales.lstg_format_name IS NOT NULL GROUP BY kylin_sales.lstg_format_name HAVING SUM(price)>5000 OR COUNT(*)>20;
  17. SELECT lstg_format_name, SUM(price) AS gmv, COUNT(1) AS trans_cnt FROM kylin_sales WHERE lstg_format_name='FP-GTC' GROUP BY lstg_format_name ORDER BY lstg_format_name LIMIT 10;

EXPRESSION

在 SELECT 语句中的表达式。 可以使用 * 选择表中的所有列。
例子：
1. *
2. 将 ID 作为值
3. 值 + 1

SUBQUERY

例子：

  1. SELECT cal_dt ,sum(price) AS sum_price FROM (SELECT kylin_cal_dt.cal_dt, kylin_sales.price FROM kylin_sales INNER JOIN kylin_cal_dt AS kylin_cal_dt ON kylin_sales.part_dt = kylin_cal_dt.cal_dt INNER JOIN kylin_category_groupings ON kylin_sales.leaf_categ_id = kylin_category_groupings.leaf_categ_id AND kylin_sales.lstg_site_id = kylin_category_groupings.site_id) t GROUP BY cal_dt;

JOIN

INNER JOIN

在表中存在至少一个匹配时，INNER JOIN 关键字返回行。
例子：

  1. SELECT kylin_cal_dt.cal_dt, kylin_sales.price FROM kylin_sales INNER JOIN kylin_cal_dt AS kylin_cal_dt ON kylin_sales.part_dt = kylin_cal_dt.cal_dt;

LEFT JOIN

使用 LEFT JOIN 关键字会从左表 (kylin_sales) 那里返回所有的行，即使在右表 (kylin_category_groupings) 中没有匹配的行。
例子：

  1. SELECT seller_id FROM kylin_sales LEFT JOIN kylin_category_groupings AS kylin_category_groupings ON kylin_sales.leaf_categ_id = kylin_category_groupings.leaf_categ_id AND kylin_sales.lstg_site_id = kylin_category_groupings.site_id WHERE lstg_format_name='FP-GTC' GROUP BY seller_id LIMIT 20;

UNION

UNION 操作符用于合并两个或多个 SELECT 语句的结果集。
注意 UNION 内部的 SELECT 语句必须拥有相同数量的列。列也必须拥有相似的数据类型。同时，每条 SELECT 语句中的列的顺序必须相同。
默认地，UNION 操作符选取不同的值。如果允许重复的值，请使用 UNION ALL。

例子：

  1. SELECT SUM(price) AS x, seller_id, COUNT(*) AS y FROM kylin_sales WHERE part_dt < DATE '2012-08-01' GROUP BY seller_id UNION (SELECT SUM(price) AS x, seller_id, COUNT(*) AS y FROM kylin_sales WHERE part_dt > DATE '2012-12-01' GROUP BY seller_id);

UNION ALL

UNION ALL 命令和 UNION 命令几乎是等效的，不过 UNION ALL 命令会列出所有的值。

例子：

  1. SELECT COUNT(trans_id) AS trans_id FROM kylin_sales AS test_a WHERE trans_id <> 1 UNION ALL SELECT COUNT(trans_id) AS trans_id FROM kylin_sales AS test_b;

COUNT

用于返回与指定条件匹配的行数。

COUNT(COLUMN)

例子：

  1. SELECT COUNT(seller_id) FROM kylin_sales;

COUNT(*)

例子：

  1. SELECT COUNT(*) FROM kylin_sales;

COUNT_DISTINCT

例子：

  1. SELECT COUNT(DISTINCT seller_id) AS DIST_SELLER FROM kylin_sales;

MAX

返回一列中的最大值。NULL 值不包括在计算中。
例子：

  1. SELECT MAX(lstg_site_id) FROM kylin_sales;

MIN

返回一列中的最小值。NULL 值不包括在计算中。
例子：

  1. SELECT MIN(lstg_site_id) FROM kylin_sales;

PERCENTILE

例子：

  1. SELECT seller_id, PERCENTILE(price, 0.5) FROM kylin_sales GROUP BY seller_id;
  3. SELECT seller_id, PERCENTILE_APPROX(price, 0.5) FROM kylin_sales GROUP BY seller_id;

SUM

返回数值列的总数。
例子：

  1. SELECT SUM(price) FROM kylin_sales;

TOP_N

例子：

  1. SELECT SUM(price) AS gmv
  2.  FROM kylin_sales 
  3. INNER JOIN kylin_cal_dt AS kylin_cal_dt
  4.  ON kylin_sales.part_dt = kylin_cal_dt.cal_dt
  5.  INNER JOIN kylin_category_groupings
  6.  ON kylin_sales.leaf_categ_id = kylin_category_groupings.leaf_categ_id AND kylin_sales.lstg_site_id = kylin_category_groupings.site_id
  7.  WHERE kylin_cal_dt.cal_dt between DATE '2013-09-01' AND DATE '2013-10-01' AND (lstg_format_name='FP-GTC' OR 'a' = 'b')
  8.  GROUP BY kylin_cal_dt.cal_dt;
  10. SELECT kylin_sales.part_dt, seller_id
  11. FROM kylin_sales
  12. INNER JOIN kylin_cal_dt AS kylin_cal_dt
  13. ON kylin_sales.part_dt = kylin_cal_dt.cal_dt
  14. INNER JOIN kylin_category_groupings
  15. ON kylin_sales.leaf_categ_id = kylin_category_groupings.leaf_categ_id
  16. AND kylin_sales.lstg_site_id = kylin_category_groupings.site_id 
  17. GROUP BY 
  18. kylin_sales.part_dt, kylin_sales.seller_id ORDER BY SUM(kylin_sales.price) DESC LIMIT 20;

WINDOW

WINDOW 函数在和当前行相关的一组表行上执行计算。
注意：WINDOW 函数中必须有 OVER 子句

ROW_NUMBER

例子：

  1. SELECT lstg_format_name, SUM(price) AS gmv, ROW_NUMBER() OVER() FROM kylin_sales GROUP BY lstg_format_name;

AVG

返回数值列的平均值。NULL 值不包括在计算中。
例子：

  1. SELECT lstg_format_name, AVG(SUM(price)) OVER(PARTITION BY lstg_format_name) FROM kylin_sales GROUP BY part_dt, lstg_format_name;

RANK

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price), RANK() OVER(PARTITION BY lstg_format_name ORDER BY part_dt) AS "rank" FROM kylin_sales GROUP BY part_dt, lstg_format_name;

DENSE_RANK

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price), DENSE_RANK() OVER(PARTITION BY lstg_format_name ORDER BY part_dt) AS "dense_rank" FROM kylin_sales GROUP BY part_dt, lstg_format_name;

FIRST_VALUE

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, FIRST_VALUE(SUM(price)) OVER(PARTITION BY lstg_format_name ORDER BY part_dt) AS "first" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

LAST_VALUE

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, LAST_VALUE(SUM(price)) OVER(PARTITION BY lstg_format_name ORDER BY part_dt) AS "current" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

LAG

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, LAG(SUM(price), 1, 0.0) OVER(PARTITION BY lstg_format_name ORDER BY part_dt) AS "prev" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

LEAD

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, LEAD(SUM(price), 1, 0.0) OVER(PARTITION BY lstg_format_name ORDER BY part_dt) AS "next" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

NTILE

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, NTILE(4) OVER (PARTITION BY lstg_format_name ORDER BY part_dt) AS "quarter" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

CASE WHEN

例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, (CASE LAG(SUM(price), 1, 0.0) OVER(PARTITION BY lstg_format_name ORDER BY part_dt) WHEN 0.0 THEN 0 ELSE SUM(price)/LAG(SUM(price), 1, 0.0) OVER(PARTITION BY lstg_format_name ORDER BY part_dt) END) AS "prev" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

CAST

RANGE，INTERVAL 关键字指明了范围。PRECEDING 表示前几天（秒/分/时/月/年）。FOLLOWING 表示后几天（秒/分/时/月/年）。
例子：

  1. SELECT part_dt, lstg_format_name, SUM(price) AS gmv, FIRST_VALUE(SUM(price)) OVER (PARTITION BY lstg_format_name ORDER BY CAST(part_dt AS timestamp) RANGE INTERVAL '3' DAY PRECEDING) AS "prev 3 days", LAST_VALUE(SUM(price)) OVER (PARTITION BY lstg_format_name ORDER BY CAST(part_dt AS timestamp) RANGE INTERVAL '3' DAY FOLLOWING) AS "next 3 days" FROM kylin_sales WHERE part_dt < '2012-02-01' GROUP BY part_dt, lstg_format_name;

SUBSTRING

例子：

  1. SELECT SUBSTRING(lstg_format_name, 1) FROM kylin_sales;

COALESCE

例子：

  1. SELECT COALESCE(lstg_format_name, '888888888888') FROM kylin_sales;

数据类型

ANYCHARVARCHARSTRINGBOOLEAN
BYTEBINARYINTSHORTLONG
INTEGERTINYINTSMALLINTBIGINTTIMESTAMP
FLOATREALDOUBLEDECIMALDATETIME
NUMERICDATETIME