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Unverified 提交 03c4ec3b authored 作者: Evgenij Ryazanov's avatar Evgenij Ryazanov 提交者： GitHub
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Merge pull request #1716 from katzyn/dml 

Improve documentation of some DML commands
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h2/src/docsrc/help/help.csv
浏览文件 @ 03c4ec3b
# Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
# and the EPL 1.0 (http://h2database.com/html/license.html).
# Initial Developer: H2 Group
"SECTION","TOPIC","SYNTAX","TEXT","EXAMPLE"
"Commands (DML)","SELECT","
SELECT [ TOP term [ PERCENT ] [ WITH TIES ] ]
[ DISTINCT [ ON ( expression [,...] ) ] | ALL ]
......@@ -20,26 +22,37 @@ selectExpression [,...]
[ FOR UPDATE ]
","
Selects data from a table or multiple tables.
WHERE filters rows before other operations.
GROUP BY groups the result by the given expression(s).
Command is executed in the following logical order:
1. Data is taken from table value expressions that are specified in the FROM clause, joins are executed.
If FROM clause is not specified a single row is constructed.
2. WHERE filters rows. Aggregate or window functions are not allowed in this clause.
3. GROUP BY groups the result by the given expression(s).
If GROUP BY clause is not specified, but non-window aggregate functions are used or HAVING is specified
all rows are grouped together.
Aggregate functions are evaluated, SAMPLE_SIZE limits the number of rows read.
HAVING filters rows after grouping and evaluation of aggregate functions.
Window functions are evaluated.
QUALIFY filters rows after evaluation of window functions.
4. Aggregate functions are evaluated, SAMPLE_SIZE limits the number of rows read.
5. HAVING filters rows after grouping and evaluation of aggregate functions.
Non-window aggregate functions are allowed in this clause.
6. Window functions are evaluated.
DISTINCT removes duplicates.
7. QUALIFY filters rows after evaluation of window functions.
Aggregate and window functions are allowed in this clause.
UNION, EXCEPT (MINUS), and INTERSECT combine the result of this query with the results of another query.
8. DISTINCT removes duplicates. If DISTINCT ON is used only the specified expressions are checked for duplicates.
9. UNION, EXCEPT (MINUS), and INTERSECT combine the result of this query with the results of another query.
Multiple set operators (UNION, INTERSECT, MINUS, EXCEPT) are evaluated from left to right.
For compatibility with other databases and future versions of H2 please use parentheses.
ORDER BY sorts the result by the given column(s) or expression(s).
10. ORDER BY sorts the result by the given column(s) or expression(s).
Number of rows in output can be limited either with standard OFFSET / FETCH,
11. Number of rows in output can be limited either with standard OFFSET / FETCH,
with non-standard LIMIT / OFFSET, or with non-standard TOP clauses.
Different clauses cannot be used together.
OFFSET specifies how many rows to skip.
......@@ -50,6 +63,9 @@ and should be an integer value between 0 and 100 inclusive.
WITH TIES can be used only together with ORDER BY and means that all additional rows that have the same sorting position
as the last row will be also returned.
WINDOW clause specifies window definitions for window functions and window aggregate functions.
This clause can be used to reuse the same definition in multiple functions.
If FOR UPDATE is specified, the tables or rows are locked for writing.
This clause is not allowed in DISTINCT queries and in queries with non-window aggregates, GROUP BY, or HAVING clauses.
When using default MVStore engine only the selected rows are locked as in an UPDATE statement;
......@@ -136,7 +152,7 @@ EXPLAIN SELECT * FROM TEST WHERE ID=1
"Commands (DML)","MERGE","
MERGE INTO tableName [ ( columnName [,...] ) ]
[ KEY ( columnName [,...] ) ]
{ VALUES { ( { DEFAULT | expression } [,...] ) } [,...] | select }
{ insertValues | select }
","
Updates existing rows, and insert rows that don't exist. If no key column is
specified, the primary key columns are used to find the row. If more than one
......@@ -250,19 +266,36 @@ Lists the schemas, tables, or the columns of a table.
SHOW TABLES
"
"Commands (DML)","Explicit TABLE","
"Commands (DML)","Explicit table","
TABLE [schemaName.]tableName
[ ORDER BY order [,...] ]
[ OFFSET expression { ROW | ROWS } ]
[ FETCH { FIRST | NEXT } [ expression [ PERCENT ] ] { ROW | ROWS }
{ ONLY | WITH TIES } ]
","
Selects data from a table.
This command is an equivalent to SELECT * FROM tableName.
FROM, WHERE, GROUP BY, HAVING, QUALIFY, and WINDOW clauses from the SELECT command are not allowed.
See SELECT command for description of ORDER BY, OFFSET, and FETCH.
","
TABLE TEST;
TABLE TEST ORDER BY ID FETCH FIRST ROW ONLY;
"
"Commands (DML)","Table value","
VALUES rowValueExpression [,...]
[ ORDER BY order [,...] ]
[ OFFSET expression { ROW | ROWS } ]
[ FETCH { FIRST | NEXT } [ expression [ PERCENT ] ] { ROW | ROWS }
{ ONLY | WITH TIES } ]
","
A list of rows that can be used like a table.
See SELECT command for description of ORDER BY, OFFSET, and FETCH.
The column list of the resulting table is C1, C2, and so on.
","
VALUES (1, 'Hello'), (2, 'World');
"
"Commands (DML)","WITH","
WITH [ RECURSIVE ] { name [( columnName [,...] )] AS ( select ) [,...] }
{ select | insert | update | merge | delete | createTable }
......@@ -2396,15 +2429,22 @@ NAME
"Other Grammar","Insert columns and source","
{ [ ( columnName [,...] ) ]
{ VALUES { ( { DEFAULT | expression } [,...] ) } [,...]
| [ DIRECT ] [ SORTED ] select } } |
{ SET { columnName = { DEFAULT | expression } } [,...] }
{ insertValues | [ DIRECT ] [ SORTED ] select | DEFAULT VALUES } }
| { SET { columnName = { DEFAULT | expression } } [,...] }
","
Names of columns and their values for INSERT statement.
","
(ID, NAME) VALUES (1, 'Test')
"
"Other Grammar","Insert values","
VALUES { DEFAULT|expression | [ROW] ({DEFAULT|expression} [,...]) }, [,...]
","
Values for INSERT statement.
","
VALUES (1, 'Test')
"
"Other Grammar","Int","
[ + | - ] number
","
......@@ -2557,11 +2597,13 @@ COMPRESSION LZF
"Other Grammar","Row value expression","
ROW (expression, [,...])
| ( [ expression, expression [,...] ] )
| expression
","
A row value expression.
","
ROW (1)
(1, 2)
1
"
"Other Grammar","Select Expression","
......@@ -2629,15 +2671,6 @@ columns with the same name.
TEST AS T LEFT JOIN TEST AS T1 ON T.ID = T1.ID
"
"Other Grammar","Values Expression","
VALUES { ( expression [,...] ) } [,...]
","
A list of rows that can be used like a table.
The column list of the resulting table is C1, C2, and so on.
","
SELECT * FROM (VALUES(1, 'Hello'), (2, 'World')) AS V;
"
"Other Grammar","Wildcard expression","
{* | tableAlias.*} [EXCEPT ([tableAlias.]columnName, [,...])]
","
......
h2/src/main/org/h2/command/Parser.java
浏览文件 @ 03c4ec3b
......@@ -1175,7 +1175,7 @@ public class Parser {
} while (readIfMore(true));
read(EQUAL);
Expression expression = readExpression();
if (columns.size() == 1) {
if (columns.size() == 1 && expression.getType().getValueType() != Value.ROW) {
// the expression is parsed as a simple value
command.setAssignment(columns.get(0), expression);
} else {
......@@ -1678,8 +1678,7 @@ public class Parser {
}
if (readIf("DEFAULT")) {
read(VALUES);
Expression[] expr = {};
command.addRow(expr);
command.addRow(new Expression[0]);
} else if (readIf(VALUES)) {
parseValuesForCommand(command);
} else if (readIf("SET")) {
......
h2/src/test/org/h2/test/scripts/TestScript.java
浏览文件 @ 03c4ec3b
......@@ -158,7 +158,7 @@ public class TestScript extends TestDb {
testScript("ddl/" + s + ".sql");
}
for (String s : new String[] { "delete", "error_reporting", "insert", "insertIgnore", "merge", "mergeUsing",
"replace", "script", "select", "show", "table", "with" }) {
"replace", "script", "select", "show", "table", "update", "values", "with" }) {
testScript("dml/" + s + ".sql");
}
for (String s : new String[] { "help" }) {
......
h2/src/test/org/h2/test/scripts/dml/select.sql
浏览文件 @ 03c4ec3b
......@@ -532,47 +532,6 @@ SELECT * FROM TEST WHERE (A, B) = (VALUES (11, 12));
DROP TABLE TEST;
> ok
VALUES (1, 2);
> C1 C2
> -- --
> 1 2
> rows: 1
VALUES ROW (1, 2);
> C1 C2
> -- --
> 1 2
> rows: 1
VALUES 1, 2;
> C1
> --
> 1
> 2
> rows: 2
SELECT * FROM (VALUES (1::BIGINT, 2)) T (A, B) WHERE (A, B) IN (VALUES(1, 2));
> A B
> - -
> 1 2
> rows: 1
SELECT * FROM (VALUES (1000000000000, 2)) T (A, B) WHERE (A, B) IN (VALUES(1, 2));
> A B
> - -
> rows: 0
SELECT * FROM (VALUES (1, 2)) T (A, B) WHERE (A, B) IN (VALUES(1::BIGINT, 2));
> A B
> - -
> 1 2
> rows: 1
SELECT * FROM (VALUES (1, 2)) T (A, B) WHERE (A, B) IN (VALUES(1000000000000, 2));
> A B
> - -
> rows: 0
CREATE TABLE TEST(A BIGINT, B INT) AS VALUES (1::BIGINT, 2);
> ok
......
h2/src/test/org/h2/test/scripts/dml/update.sql 0 → 100644
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-- Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
-- and the EPL 1.0 (http://h2database.com/html/license.html).
-- Initial Developer: H2 Group
--
CREATE TABLE TEST(A INT, B INT);
> ok
INSERT INTO TEST VALUES (1, 2);
> update count: 1
UPDATE TEST SET (A, B) = (3, 4);
> update count: 1
SELECT * FROM TEST;
> A B
> - -
> 3 4
> rows: 1
UPDATE TEST SET (B) = 5;
> update count: 1
SELECT B FROM TEST;
>> 5
UPDATE TEST SET (B) = ROW (6);
> update count: 1
SELECT B FROM TEST;
>> 6
UPDATE TEST SET (B) = (7);
> update count: 1
SELECT B FROM TEST;
>> 7
DROP TABLE TEST;
> ok
h2/src/test/org/h2/test/scripts/dml/values.sql 0 → 100644
浏览文件 @ 03c4ec3b
-- Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
-- and the EPL 1.0 (http://h2database.com/html/license.html).
-- Initial Developer: H2 Group
--
VALUES (1, 2);
> C1 C2
> -- --
> 1 2
> rows: 1
VALUES ROW (1, 2);
> C1 C2
> -- --
> 1 2
> rows: 1
VALUES 1, 2;
> C1
> --
> 1
> 2
> rows: 2
VALUES 4, 3, 1, 2 ORDER BY 1 FETCH FIRST 75 PERCENT ROWS ONLY;
> C1
> --
> 1
> 2
> 3
> rows (ordered): 3
SELECT * FROM (VALUES (1::BIGINT, 2)) T (A, B) WHERE (A, B) IN (VALUES(1, 2));
> A B
> - -
> 1 2
> rows: 1
SELECT * FROM (VALUES (1000000000000, 2)) T (A, B) WHERE (A, B) IN (VALUES(1, 2));
> A B
> - -
> rows: 0
SELECT * FROM (VALUES (1, 2)) T (A, B) WHERE (A, B) IN (VALUES(1::BIGINT, 2));
> A B
> - -
> 1 2
> rows: 1
SELECT * FROM (VALUES (1, 2)) T (A, B) WHERE (A, B) IN (VALUES(1000000000000, 2));
> A B
> - -
> rows: 0
h2/src/test/org/h2/test/scripts/functions/system/table.sql
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......@@ -3,10 +3,10 @@
-- Initial Developer: H2 Group
--
select * from table(a int=(1)), table(b int=(2));
> A B
> - -
> 1 2
select * from table(a int=(1)), table(b int=2), table(c int=row(3));
> A B C
> - - -
> 1 2 3
> rows: 1
create table test as select * from table(id int=(1, 2, 3));
......
h2/src/test/org/h2/test/scripts/other/help.sql
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......@@ -16,11 +16,11 @@ HELP ABCDE EF_GH;
HELP HELP;
> ID SECTION TOPIC SYNTAX TEXT
> -- ---------------- ----- ----------------------- ----------------------------------------------------
> 66 Commands (Other) HELP HELP [ anything [...] ] Displays the help pages of SQL commands or keywords.
> 67 Commands (Other) HELP HELP [ anything [...] ] Displays the help pages of SQL commands or keywords.
> rows: 1
HELP he lp;
> ID SECTION TOPIC SYNTAX TEXT
> -- ---------------- ----- ----------------------- ----------------------------------------------------
> 66 Commands (Other) HELP HELP [ anything [...] ] Displays the help pages of SQL commands or keywords.
> 67 Commands (Other) HELP HELP [ anything [...] ] Displays the help pages of SQL commands or keywords.
> rows: 1
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