Chapter 6. SQL Syntax

Index:

  1. Select
  2. Insert
  3. Update
  4. Delete
  5. CREATE CATALOG
  6. CREATE DATABASE
  7. DROP DATABASE
  8. TRUNCATE DATABASE
  9. PACK DATABASE
  10. CREATE TABLE
  11. DROP TABLE
  12. ALTER TABLE
  13. TRUNCATE TABLE
  14. PACK TABLE
  15. RENAME TABLE
  16. LOCK TABLE
  17. UNLOCK TABLE
  18. CREATE INDEX
  19. DROP INDEX
  20. REINDEX
  21. CREATE VIEW
  22. DROP VIEW
  23. CREATE SEQUENCE
  24. DROP SEQUENCE
  25. ALTER SEQUENCE
  26. SET TRANSACTION
  27. START TRANSACTION
  28. COMMIT
  29. ROLLBACK
  30. SAVEPOINT
  31. RELEASE SAVEPOINT
  32. Call Procedure
  33. Pseudo Tables
  34. Pseudo Columns
  35. Declare Variable
  36. SET Variable
  37. Comment Syntax
  38. SQL States

Use ";" to separate multi sql statements. For instance, "insert into test (int1) values(1);insert into test (int1) values(2);". "reserved word", [reserved word] or {v 'reserved word'} is used to quote a column with reserved word name in SQL statement, for instance, 'select {v 'RIGHT'},'other' from states where {v 'RIGHT'}=32. The HXTT Access supports using DATE, TIME, TIMESTAMP, GROUP, ORDER, KEY, DESC, SEQUENCE, INCREMENT, MINVALUE, MAXVALUE, CACHE, CHECK, CYCLE, OTHER, SET, INT, UNIQUE, LEVEL, RELEASE, INDEX, TOP, PACK, CALL, CONNECT, START, PRIMARY, COMMENT, TRANSACTION, REFERENCES, and UPDATE directly in SQL, although they're reserved words too.

SELECT [ALL | DISTINCT [ ON ( expression [, ...] ) ] ] | DISTINCTROW [TOP n [PERCENT]] select_list [INTO variable [, ...] | INTO OUTFILE 'outfileName' ] FROM table_reference_list [WHERE condition_expression] [[START WITH initial-condition] CONNECT BY [NOCYCLE] recurse-condition] [group_by_clause] [HAVING condition_expression] [union_clause] [order_by_clause] [LIMIT [offset,] [limit] ] [FOR UPDATE]

select_list: { expression [ [AS] columnAlias] | table.* | * } [,...]

table_reference_list: {table_reference | table_join} [,...]

table_reference: { { table_name | subquery | (table_join) | (VALUES expression[, ...] ) AS tableName(columnName[,...])} [ [AS] tableAlias] } [pivot_clause] [unpivot_clause]

table_name: { [catalog.]tableName} | {UNC path}

table_join: table_reference join_clause [join_clause,...]

join_clause: [NATURAL] { INNER | { [ LEFT | RIGHT | FULL] [OUTER] } } JOIN table_reference [ ON condition_expression | USING(column1,column2,...) ]

condition_expression: an expression which should return a boolean value.

pivot_clause: PIVOT ( aggregate_function(value_column) FOR pivot_expr IN (column_list) ) [AS] tableAlias

unpivot_clause: UNPIVOT ( value_column FOR pivot_column IN (column_list) ) [AS] tableAlias

group_by_clause: GROUP BY expression [,...] [WITH ROLLUP | CUBE]

union_clause: { UNION | INTERSECT | EXCEPT | MINUS } [ ALL ] select_statement [ union_clause ...]

order_by_clause: ORDER BY expression [ASC|DESC] [,...]

DISTINCT specifies that duplicate rows are discarded. A duplicate row is when each corresponding select_list column has the same value. DISTINCT has no effect on constant, and _rowid_. For instance, "select distinct 'First Name',name,age from users". 'First Name' will be ignored since it's a constant.

expression: a complicated expression which can include parentheses, logical operator(NOT, AND, OR), positives/minus sign(+, -), arithmetical operator(+,-,*,/,%), string operator(|| (left string concat right string), +(left string concat right string), -(trim left string then concat rightstring), $(check whether left string is contained in right string), condition operator(>, >=, =, ==, <=, <, !=, <>), bitwise logical operator(&, |, ~, ^, <<, >>), [NOT] LIKE pattern {escape 'escape_character'},[NOT] ILIKE pattern {escape 'escape_character'}, IS [NOT] NULL, BETWEEN ... AND ..., [NOT] IN, [NOT] EXISTS, [ALL|ANY|SOME] (subquery), [NOT] CASE WHEN expr THEN result [WHEN expr THEN result ...] [ELSE expr] END, CASE expr WHEN compare_expr THEN result [WHEN compare_expr THEN result ...] [ELSE result] END, SQL Escape Syntax({d 'yyyy-mm-dd'}, {t 'hh:mm:ss'}, {ts 'yyyy-mm-dd hh:mm:ss.f...'},{v 'reserved_word'}, {fn functionExpression}, {escape 'oneEcapeCharacter'}, {"varbinary" 'string'}), function(more than 200), aggregate function(MAX, MIN, AVG, COUNT, SUM, STD, STDDEV), constant(null, true, false, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, date, time, timestamp, number, string), column, parameter(?), subquery(single-row subquery, multirow subquery, multiple-column subquery, inline views, correlated subquery) and so on.

"SELECT select_list" can be used to get some calculated values through an one-row ResultSet. Column can be used in all sql except for "SELECT select_list". Parameter(?) can only be used in PreparedStatement.

For instance:

select val('123.222')
select CONVERT('123',SQL_INTEGER) as a,TTOC({d '1999-10-10'},1) as b, IFNULL(1,33) as c, 123 in(456,123,789,'abc') as d, EXTRACT(DECADE FROM '2001-02-16 20:38:40'), '88'+IIF(3<6,'1','0')
select encode('adsdfsdf');
select decode(encode('adsdfsdf'))+'';
SELECT top 8 percent * FROM data.sz9010;
SELECT * FROM "data"."testtable"; SELECT * FROM "datadir\data"."testtable"; select distinct top 10 * from test where not deleted() order by int1,char1 desc;
select int1,float1 from test where int1>0 group by int1,double1;
select distinct on (int1) int1,double1 from test;
select sum(int1),max(dec1),min(double1) from test;
SELECT SUM(apmast.fnamount), SUM(glcshi.fnadjamt),SUM(glcshi.fncashamt),SUM(glcshi.fndiscount) FROM apmast, glcshi WHERE apmast.fcinvoice +apmast.fvendno = glcshi.fcinvoice + glcshi.fcnameid AND apmast.fduedate between {d '1999-01-01'} AND {d '1999-11-30'} AND apmast.finvdate <= {d '1999-11-30'};
SELECT cellID, columnID, reference, function, parameter FROM repLayout WHERE reportID = '1' AND rowID = 0 ORDER BY columnID;
select distinct int1,double1 from test group by int1,double1,float1;
select distinct * from test where int1>0
select distinct int1,count(*),sum(int1) from brain.user group by int1
SELECT date1,time1,int1 FROM test where TIMESTAMPdIFF(SQL_TSI_YEAR,time1,{ts '3999-03-24 00:59:23.22222'})<-2000 and date1>{d '1900-01-01'} and date1>{d '1960-01-01'} and date1<{d '2000-01-02'}+20;
select int1 as a,c+23 as b,a+b as c from test where a=1;
SELECT INT1,FLOAT1,A.* FROM TEST A WHERE {fn abs(-TEST.INT1)}>0 or a.float1<0 order by int1 asc,currency1,double1*5+int1 desc;
select int1,count(*),sum(int1+count(*)),sum(int1)+int1 from test group by int1 having int1>10;
SELECT SCHOOLNUM, STULINK,CHGNUMBER, {v 'ABSEN$0101'}, {v 'ABSEN$0102'}, USERSTAMP, DATESTAMP, {v 'TIMESTAMP'},SEQUENCE FROM AATD2019 where {v 'ABSEN$0101'}='1234' ORDER BY SCHOOLNUM, STULINK, SEQUENCE;
select char1,char1 like 'Z%',char1 in('ZZAA','Z'),char1 between 'A' and 'ZZZ',char1 in('ZZAA','Z') or char1 between 'A' and 'Z',* from test where char1='Z';
select int1 from test where int1=(select distinct top 1 int1 from test where int1>0);
select int1 from test where int1 in(select int1 from test where not deleted());
select recno(),int1 from test where (recno(),int1) in(select top 2 recno(),int1 from test where int1>0);
select subquery.int1,recno('subquery') from (select top 2 recno(),int1 from test where int1>0) as subquery;
select subquery.int1,recno('test'),test.int1,recno('subquery') from (select top 2 recno(),int1 from test where int1>0) as subquery, test where test.int1=subquery.int1;
ELECT INT1 FROM test as a WHERE EXISTS(SELECT 1 FROM test WHERE int1 >0);
SELECT INT1 FROM test as a WHERE int1>=all(SELECT int1 FROM test);
SELECT INT1 FROM test as a WHERE int1>=any(SELECT int1 FROM test);
SELECT INT1 FROM test as a WHERE int1>=some(SELECT int1 FROM test);
select int1,recno() from test where (int1,recno())>(3,5);
select int1,recno() from test where (recno(),int1)=(6,222);
SELECT * FROM (SELECT * FROM test WHERE int1 = 222 ) as a WHERE EXISTS(SELECT 1 FROM test WHERE int1 >0);
select recno('a'),recno('b'),a.int1,a.char1,b.int1,b.char1 from test a, test as b where recno('a')=recno('b');
select a.int1,a.char1,b.int1,b.char1 from test a inner join test as b on a.int1=b.int1;
select a.int1,a.char1,b.int1,b.char1 from test a NATURAL inner join test as b on a.int1=b.int1;
select recno('a'),recno('b'),a.int1,a.char1,b.int1,b.char1 from test a left join test as b on a.int1=b.int1;
select a.int1,a.char1,b.int1,b.char1 from test a right join test as b on a.int1=b.int1;
select a.int1,a.char1,b.int1,b.char1 from test a full join test as b on a.int1=b.int1;
select recno('a'),recno('b'),a.int1,a.char1,b.int1,b.char1 from test a full join test as b on a.int1==b.int1 and recno('a')!=recno('b');
SELECT * FROM test a LEFT JOIN (test b JOIN test c ON (b.int1 = c.int1)) as d ON (a.int1 = d.int1);
SELECT * FROM test a,test b,test c WHERE a.int1 = b.int1 AND b.int1 = c.int1;
SELECT * FROM test a NATURAL CROSS JOIN test b CROSS JOIN test c WHERE a.int1 = b.int1 AND b.int1 = c.int1;
SELECT * FROM test a LEFT JOIN (test b JOIN test c ON (b.int1 = c.int1)) on recno('a')=recno(2);
SELECT int1 FROM test where int1>0 UNION ALL select int1 from test where int1>3000 order by int1 desc
SELECT int1,* FROM test where int1>0 UNION select int1,* from test where int1>3000 order by int1
ELECT int1,* FROM test where int1>0 INTERSECT all select int1,* from test where int1>3000 order by int1;
SELECT int1,* FROM test where int1>0 EXCEPT select int1,* from test where int1>3000 order by int1 descl
SELECT int1,* FROM test where int1>0 MINUS select int1,* from test where int1>3000 order by int1,double1 desc;
select double1,sum(double1),int1 from test where int1>0 group by int1 having sum(double1)>0 and double1>0;
select distinct 1,a.int1,sum(a.int1) from test as a,test as b group by a.int1,B.int1
select a.int1,a.char1,b.int1,b.char1 from test a NATURAL inner join test as b
select * from (select 'ab5' as a) where a like '%[a-c][^ac][12345]'
select lpad(' ',2*(level-1)) || str(child) s from test_connect_by start with parent=0 connect by prior child = parent;

INSERT INTO table_name [ [AS] tableAlias] [ ( column_identifier [,...] ) ] { VALUES ( expression [, ...] ) | VALUES expression [, ...] | VALUES ( expression [, ...] ),... | SELECT query | ? }

column_identifier = columnName | "reserved_word" | {v 'reserved_word'}

Adds one or more new rows of data into a table. SQL does't permit that table1 is the same table as table2 when INSERT INTO table1 select * from table2, but the HXTT Access support such an unadvisable operation, for example, INSERT INTO test (INT1,DATE1) select distinct int1,date1 from test.

For instance:

INSERT INTO test (INT1,dec1,time1) VALUES(-1999,-222.33333,{ts '1333-11-30 22:22:22.999999999'});
INSERT INTO test ("INT1","DATE1") VALUES(1999.0111,{d '1996-10-21'});
INSERT INTO test ("INT1","DATE1") VALUES(1999.0111,{d '1996-10-21'}),(333,{d '2006-10-21'});
INSERT INTO test ("INT1") VALUES 1999.0111,333;
insert into ecode values('Maciej', 'Kowalski');
insert into test values (reccount()+1,'abc',date(),{ts '2003-12-18 19:42:17.88'});
INSERT INTO AATD2019 ({v 'ABSEN$0101'}) values('1234');
insert into test select * from test order by int1 asc;
insert into test select * from test order by int1 asc;

UPDATE table_name [ [AS] tableAlias] SET [column_identifier | (column_identifier,...) ] = expression [,...] [WHERE condition_expression]

For instance:

update order set buyer=(SELECT name FROM user WHERE user.id = order.buyerid);
update test set int1=null where SequenceID=26;
update test set INT1=323232,DEC1=-DEC1 where FLOAT1=3.00 and INT1=222 and DEC1=3.00 and DOUBLE1=34.0 and TIME1 is NULL and CHAR1='ZZAA' and CURRENCY1=0 and BOOLEAN1 is NULL
update AATD2019 set {v 'ABSEN$0101'}='1234' where SequenceID=1;
update test set int1=3333555 where exists(SELECT 1 FROM test WHERE int1 = 222 ) and SequenceID=3;
UPDATE "UIP_Target" SET ("key_string","key_int","data_string","data_int","data_decimal" ) = (SELECT COALESCE(DP3475."key_string", "UIP_Target"."key_string"),COALESCE(DP3475."key_int", "UIP_Target"."key_int"),COALESCE(DP3475."data_string", "UIP_Target"."data_string"),COALESCE(DP3475."data_int", "UIP_Target"."data_int"),COALESCE(DP3475."data_decimal", "UIP_Target"."data_decimal") FROM DP3475 WHERE "UIP_Target"."key_string"=DP3475."KEY208" AND "UIP_Target"."key_int"=DP3475."KEY572");
UPDATE "UIP_Target" SET ("key_string","key_int","data_string","data_int","data_decimal" ) = (SELECT COALESCE(DP3475."key_string", "UIP_Target"."key_string"),COALESCE(DP3475."key_int", "UIP_Target"."key_int"),COALESCE(DP3475."data_string", "UIP_Target"."data_string"),COALESCE(DP3475."data_int", "UIP_Target"."data_int"),COALESCE(DP3475."data_decimal", "UIP_Target"."data_decimal") FROM DP3475 WHERE "UIP_Target"."key_string"=DP3475."KEY208" AND "UIP_Target"."key_int"=DP3475."KEY572") WHERE EXISTS (SELECT 'X' FROM DP3475 WHERE "UIP_Target"."key_string"=DP3475."KEY208" AND "UIP_Target"."key_int"=DP3475."KEY572")
UPDATE "UIP_Target" SET ("data_string","data_int","data_decimal" ) = (date(),789,44.5) WHERE EXISTS (SELECT 'X' FROM DP3475 WHERE "UIP_Target"."key_string"=DP3475."KEY208" AND "UIP_Target"."key_int"=DP3475."KEY572")

DELETE FROM table_name [ [AS] tableAlias] [WHERE condition_expression]

Removes rows in a table according to condition_expression.

For instance:

delete from test where SequenceID=4;

CREATE CATALOG [IF NOT EXISTS] catalogName

Create a subdirectory to contain database files.

For instance:

create catalog if not exists data222;

CREATE DATABASE [IF NOT EXISTS] databaseName

Create a new MS ACCESS MDB(ACCDB) database, you can assign which JET engine(JET3, JET4, or JET5) database would be created by assign the versionNumber property when build connection, it wil create JET4 engine database by default; the URL format must be assigned as a directory, for example, "jdbc:access:////usr/data"

create database if not exists testmdb;

DROP DATABASE [IF EXISTS] databaseName

The DROP DATABASE statement is used to delete a database. IF that database doesn't exist without using IF EXIST, an SQLException will be thrown.

TRUNCATE DATABASE [IF EXISTS] databaseName

Remove all data rows of common tables to get an blank database.

For instance:

truncate DATABASE db1;

PACK DATABASE [IF EXISTS] databaseName

pack the database to reduce file size.

For instance:

pack DATABASE db1;

CREATE TABLE [IF NOT EXISTS] table_name [(column_identifier data_type [constraint] [,...] [, constraint_clause [,...] ] )] [ [AS] SELECT query | ? ]

data_type: CHAR(n) | CHARACTER(n) | VARCHAR[(n)] | BINARY (n) | VARBINARY (n) | NUMERIC(n1[,n2]) | DEC[IMAL](n1[,n2]) | INT[EGER] [ AUTO_INCREMENT] | SMALLINT | FLOAT [(n)] | REAL | DOUBLE | BIT | BOOLEAN | DATE [(dateFormat)] | TIME [(dateFormat)] | TIMESTAMP [(dateFormat)] | LONGVARCHAR [(n)] | LONGVARBINARY [(n)] | JAVA_OBJECT [(n)] | CLOB | BLOB| OTHER(type_name [,n]) | NUMBER[(n1[,n2])]

n, n1,n2: positive integer, n2 can be 0

constraint: [NULL| NOT NULL] [UNIQUE] [DEFAULT expression] [PRIMARY KEY] [COMMENT 'string']

constraint_clause: [ CONSTRAINT constraint_name ] PRIMARY KEY (column1, column2, . column_n) | CONSTRAINT constraint_name FOREIGN KEY (column1, column2, ... column_n) REFERENCES parent_table (column1, column2, ... column_n) [ON DELETE CASCADE] [ON UPDATE CASCADE] | [ CONSTRAINT constraint_name ] UNIQUE (column1, column2, . column_n) | CONSTRAINT constraint_name CHECK (column_name condition)

Temporary table is only visible in the current connection.

The HXTT Access will ignore (dateFormat) for MS Access's compatibility. Column can store null values, so that constraint NOT NULL is ignored. Although CREATE INDEX can create UNIQUE and PRIMARY KEY for existent table, the preferable way is using UNIQUE and PRIMARY KEY in CREATE TABLE.

SQL Data Types for Create Table

SQL Type 

Access Data Type

Size in table

SQL Syntax

Java Type 

CHARACTER

Unavailing

1~2

CHAR[ACTER]

char

CHAR 

Text field of max width n

1~255

CHAR[ACTER](n)

String

VARCHAR 

Text field of max width n

1~255

VARCHAR (n)

String

LONGVARCHAR

Memo BLOB

 

LONGVARCHAR

String, char[], java.sql.CLOB 

NUMERIC 

NUMERIC
1~255

NUMERIC [(n[,d])]

java.math.BigDecimal 

DECIMAL 

DECIMAL
1~255

DEC[IMAL] [(n[,d])]

java.math.BigDecimal 

BIT 

Logical

1

BIT

boolean 

TINYINT

Unavailing, map TINYINT into SMALLINT

 

TINYINT

byte 

SMALLINT

Short integer
2
SMALLINT

short 

INTEGER 

Long integer

4

INT[EGER]

int 

BIGINT 

Unavailing, map BIGINT into NUMERIC(20,0)

 

BIGINT

long 

REAL 

float

4

REAL

float 

FLOAT 

Unavailing, map FLOAT into DOUBLE

 

FLOAT

double 

DOUBLE 

double

8

DOUBLE

double 

BINARY 

Unavailing, map BINARY into VARBINARY

 

BINARY (n)

byte[] 

VARBINARY 

VARBINARY

 

VARBINARY (n)

byte[]

LONGVARBINARY 

Unavailing, map LONGVARBINARY into OLE

 

LONGVARBINARY (n)

byte[], java.sql.BLOB 

DATE 

Unavailing, map DATE into TIMESTAMP

 

DATE

java.sql.Date 

TIME 

Unavailing, map TIME into TIMESTAMP

 

TIME

java.sql.Time 

TIMESTAMP 

Timestamp

8

TIMESTAMP

java.sql.Timestamp 

BOOLEAN

Logical

1

BOOLEAN

boolean

BLOB

Unavailing, map BLOB into OLE

 

BLOB

byte[], java.sql.BLOB, Object

CLOB

Unavailing, map CLOB into LONGVARCHAR

 

CLOB

String, char[], java.sql.CLOB

OTHER

Currency

OLE

8

 

OTHER (Currency)

OTHER (OLE)

java.math.BigDecimal

byte[]

JAVA_OBJECT

Unavailing, map JAVA_OBJECT into OLE

 

JAVA_OBJECT

byte[] or Object

For instance:

create table if not exists test(TAlpha varchar(25),TMoney other (currency),TShort smallint,TLongInt int,TBCD numeric(20,4),TCalc double,TDate date,TTime time, TMemo longvarchar, TOle OTHER (OLE), TLogical boolean );

DROP TABLE [IF EXISTS] table_name

Removes a table, and its indexes from the database. IF that table doesn't exist without using IF EXIST, an SQLException will be thrown.

For instance:

drop table if exists states;

ALTER TABLE table_name alter_specification [,...]

alter_specification: {{ADD|MODIFY} column_identifier data_type [constraint]}| DROP column_identifier | RENAME column_identifier 1 TO column_identifier 2 | RENAME TO table_name2 | ADD constraint_clause

When some alter operations are in one ALTER sql, the HXTT Access will complete all RENAME column operations first, then do all ADD, MODIFY, AND DROP column operations at one time, and RENAME table is the last operation.

For instance:

alter table test rename int11 to int1;
alter table test rename int1 to int2, rename to test22;
alter table test22 rename to test;
alter table test add column1 int DEFAULT 3 NULL, drop clob1, modify double1 int;

TRUNCATE TABLE [IF EXISTS] table_name

Remove all table rows.

For instance:

truncate table test;

PACK TABLE [IF EXISTS] table_name

pack the table.

For instance:

pack table test;

RENAME TABLE table_name TO table_name2

Rename the table.

For instance:

RENAME table test to test1;

LOCK TABLE table_name

lock the table. Returns 1 if sucess, 0 if failed to lock a table.

For instance:

lock table test;

UNLOCK TABLE table_name

unlock the table. Returns 1 if sucess, 0 if failed to unlock a table.

For instance:

unlock table test;

CREATE [UNIQUE] INDEX [IF NOT EXISTS] indexName[(keylength)][,...] [OF indexFileName] ON tableName (expression [UNIQUE] [PRIMARY KEY] [ASC|DESC] [FOR expression][,...])

Create an index file which can contains one or more index expressions for a table. The HXTT Access will utilize index when condition_expression contains indexed expression.

For instance:

DROP INDEX [IF EXISTS] {ALL | indexName[,...]} [of indexFileName] ON table_name

Removes the specified index from the database.

For instance:

drop index all on test;

REINDEX {ALL | indexName[,...]} ON table_name

Rebuild the specified index.

For instance:

reindex all on test;

CREATE [OR REPLACE] [ TEMP | TEMPORARY ] VIEW table [ ( column_identifier [,...] ) ] [AS ] SELECT query

Creates a virtual table whose contents (columns and rows) are defined by a query. Temporary view is only visible in the current connection.

For instance:

create or replace temporary view abcv (aaa) select FEC_ANAL FROM ANALISIS;

DROP VIEW [IF EXISTS] table

Drop a virtual table.

For instance:

drop view if exists abcv;

CREATE SEQUENCE [IF NOT EXISTS] sequence_name [AS {INT|SMALLINT|TINYINT|BIGINT}] [START [WITH] n] [INCREMENT [BY] n] [MINVALUE n | NO MINVALUE] [ MAXVALUE n | NO MAXVALUE ] [ CACHE n | NO CACHE] [ [ NO ] CYCLE ]

sequence_name: [catalog.]sequenceName

The optional clause START WITH n allows the sequence to begin anywhere. The default starting value is minvalue for ascending sequences and maxvalue for descending ones. The optional clause INCREMENT BY n specifies which value is added to the current sequence value to create a new value. A positive value will make an ascending sequence, a negative one a descending sequence. The default value is 1. The optional clause MINVALUE n determines the minimum value a sequence can generate. If this clause is not supplied or NO MINVALUE is specified, then defaults will be used. The defaults are 1 and -128(-32768,0x80000000,0x8000000000000000L) for ascending and descending sequences, respectively. The optional clause MAXVALUE n determines the maximum value for the sequence. If this clause is not supplied or NO MAXVALUE is specified, then default values will be used. The defaults are 127(32767,0x7fffffff,0x7fffffffffffffffL)and -1 for ascending and descending sequences, respectively. The optional clause CACHE cache specifies how many sequence numbers are to be preallocated and stored in memory for faster access. The minimum value is 1 (only one value can be generated at a time, i.e., no cache), and this is also the default. The maximum value for cache is 65535. The CYCLE option allows the sequence to wrap around when the maxvalue or minvalue has been reached by an ascending or descending sequence respectively. If the limit is reached, the next number generated will be the minvalue or maxvalue, respectively. If NO CYCLE is specified, any calls to nextval after the sequence has reached its maximum value will throw an exception. If neither CYCLE or NO CYCLE are specified, NO CYCLE is the default.

For instance:

create sequence if not exists userID start WITH 100 increment by 2 maxvalue 2000 cache 5 cycle;

DROP SEQUENCE [IF EXISTS] sequence_name

Removes a sequence from the database. IF that sequence doesn't exist without using IF EXIST, an SQLException will be thrown.

For instance:

drop sequence if exists userID;

ALTER SEQUENCE sequence_name [AS {INT|SMALLINT|TINYINT|BIGINT}] [RESTART [WITH] n] [INCREMENT [BY] n] [MINVALUE n | NO MINVALUE] [ MAXVALUE n | NO MAXVALUE ] [ CACHE n | NO CACHE] [ [ NO ] CYCLE ]

ALTER SEQUENCE changes the parameters of an existing sequence generator. Any parameter not specifically set in the ALTER SEQUENCE command retains its prior setting.

For instance:

alter sequence userID restart WITH 100 increment by 1 maxvalue 5000;

SET TRANSACTION transaction_mode [, ...]

transaction_mode: { ISOLATION LEVEL {READ UNCOMMITTED | READ COMMITTED | REPEATABLE READ | SERIALIZABLE } | { READ WRITE | READ ONLY }

Sets the transaction characteristics of the current transaction. It effects any subsequent transactions in the same connection. java.sql.Connection.setTransactionIsolation(int level) and java.sql.Connection.setReadOnly(boolean readOnly) can do the same task.

For instance:

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

START TRANSACTION [ transaction_mode [, ...] ]

Begins a new transaction block. java.sql.Connection.setAutoCommit(false), java.sql.Connection.setTransactionIsolation(int level), and java.sql.Connection.setReadOnly(boolean readOnly) can do the same task.

For instance:

START TRANSACTION;

COMMIT [WORK]

Terminates the current transaction and makes all changes under the transaction persistent. It commits the changes to the database. java.sql.Connection.commit() can do the same task.

For instance:

commit;

ROLLBACK [WORK] [ TO [ SAVEPOINT ] savepoint_name]

Without savepoint_name, terminates the current transaction and rescinds all changes made under the transaction. It rolls back the changes to the database. With savepoint_name, rolls back all commands that were executed after the savepoint was established. java.sql.Connection.rollback() can do the same task of ROLLBACK [WORK] sql.

For instance:

rollback;

SAVEPOINT savepoint_name

SAVEPOINT establishes a new savepoint within the current transaction. java.sql.Connection.setSavepoint(String name) and java.sql.Connection.setSavepoint() can do the same task.

For instance:

savepoint t1;

RELEASE SAVEPOINT savepoint_name

Destroys a savepoint previously defined in the current transaction. java.sql.Connection.releaseSavepoint(Savepoint savepoint) can do the same task.

For instance:

release savepoint t1;

{ [ ? = ] call procedure_name [ ( ? [, ? [ , ... ]] ) ] }

java.sql.CallableStatement can be used to call stored procedure.

For instance:

{call myview(?)};

Pseudo Tables

The INFORMATION_SCHEMA implementation include SCHEMATA, TABLES, and COLUMNS. For instance,

SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA;
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='TABLE';
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='TABLE' AND TABLE_SCHEMA='SCHEMA-NAME';
SELECT column_name,data_type,column_default,is_nullable FROM information_schema.tables AS t JOIN information_schema.columns AS c ON t.table_catalog=c.table_catalog AND t.table_schema=c.table_schema AND t.table_name=c.table_name WHERE t.table_name='TABLE-NAME';
SELECT column_name, data_type, character_maximum_length, numeric_precision, column_default, is_nullable FROM information_schema.tables as t JOIN information_schema.columns AS c ON t.table_catalog=c.table_catalog AND t.table_schema=c.table_schema AND t.table_name=c.table_name WHERE c.table_schema='TABLE-SCHEMA' AND c.table_name='TABLE-NAME';

Pseudo Columns

_rowid_, is a pseudo column as primary key. A _rowid_ identifies a row in a table.

level is a pseudo column that can be used in hierarchical queries (start with .. connect by). For records that appear in the root, level is 1, for their (direct) children, level is 2 and so on.

CURRENT_DATE is a pseudo variable which returns the current date.

CURRENT_TIME is a pseudo variable which returns the current time.

CURRENT_TIMESTAMP is a pseudo variable which returns the current timestamp.

DECLARE variable_name[,...] type [DEFAULT expression]

Variable is visiable only in the same connection.

For instance:

DECLARE abc CHAR(20) DEFAULT 'Hello';
DECLARE x, y INT;

SET variable_name = expression [,...]

expression can be a complicated expresion. BTW, INTO variable[,...] clause of SELECT syntax can set selected columns directly into variables.

For instance:

SET x = 1+int(55.5),y=2;
SELECT name,id INTO x,y FROM table1 WHERE id=33;
SELECT date(),pi() INTO x,y;
SELECT id,data INTO x,y FROM test.t1 LIMIT 1;

Comment Syntax

#one-line comment
--one-line comment
/*multiline comment*/

For instance:

select * /* column list */ from test;#This is a select sql.

SQL States

SQL State
Description
01001
Cursor operation conflict
01427
single-row subquery returns more than one row
01428
single-column subquery returns more than one column
01429
subquery returns mismatch column number
01436
CONNECT BY loop in user data
01430
single-row subquery returns none row
07006
Restricted data type attribute violation
08000
Connection exception
08003
Connection not open
08007
Connection failure during transaction
08S01
Remote database access failure
0A000
Feature not supported
0A001
Multiple server transactions
21S01
Insert value list does not match column list
22000
Data exception
22019
Invalid escape character
22023
Invalid parameter value
23000
Integrity constraint violation
24000
Invalid cursor state
25000
Invalid transaction state
26000
Invalid SQL statement name
28000
Access denied error
2A000
Direct SQL syntax error or access rule violation
2D000
Invalid transaction termination
2E000
Invalid connection name
34000
Invalid cursor name
34102
Invalid variable name
34103
Invalid funciton name
34104
Invalid index file name
3C000
Duplicate cursor name
3D000
Invalid catalog name
3F000
Invalid schema name
40000
Transaction rollback
42000
Syntax error or access violation
42001
Syntax error
42002
Access violation
42003
Statement has been closed
60000
System errors
99999
Catch all others
C0100
Unknown CodePageID
C0101
Unknown File Format
C0102
Unknown Table Version
C0103
Unknown Index Version
C0104
Corrupt Index File
C0105
Invalid Record Number
C0106
Convert dirty data into null value
S0001
Base table or view already exists
S0021
Index already exists
S0022
Column not found
S1002
Invalid column number
S1009
Invalid Argument value
S1T00
Timeout expired
HY008
Operation canceled

 

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