Yes, it is possible:
public class Foo
{
private int x;
public Foo()
{
this(1);//calling constructor -->> public Foo(int x)
}
public Foo(int x)
{
this.x = x;
}
}
public class Foo
{
private int x;
public Foo()
{
this(1);//calling constructor -->> public Foo(int x)
}
public Foo(int x)
{
this.x = x;
}
}
TOPIC | TEXT | SYNTAX | Example |
---|---|---|---|
INT Type | Possible values: -2147483648 to 2147483647. | INT | INTEGER | MEDIUMINT | INT4 | SIGNED | |
BOOLEAN Type | Possible values: TRUE and FALSE. | BOOLEAN | BIT | BOOL | |
TINYINT Type | Possible values are: -128 to 127. | TINYINT | |
SMALLINT Type | Possible values: -32768 to 32767. | SMALLINT | INT2 | YEAR | |
BIGINT Type | Possible values: -9223372036854775808 to 9223372036854775807. | BIGINT | INT8 | |
IDENTITY Type | Auto-Increment value. | IDENTITY | |
DECIMAL Type | Data type with fixed precision and scale. | { DECIMAL | NUMBER | DEC | NUMERIC } ( precisionInt [ , scaleInt ] ) | |
DOUBLE Type | Floating point number. | { DOUBLE [ PRECISION ] | FLOAT | FLOAT4 | FLOAT8 } | |
REAL Type | Single precision floating point number. | REAL | |
TIME Type | The format is hh:mm:ss. | TIME | |
DATE Type | The format is yyyy-MM-dd. | DATE | |
TIMESTAMP Type | The format is yyyy-MM-dd hh:mm:ss[. | { TIMESTAMP | DATETIME | SMALLDATETIME } | |
BINARY Type | Represents a byte array. | { BINARY | VARBINARY | LONGVARBINARY | RAW | BYTEA } [ ( precisionInt ) ] | |
OTHER Type | This type allows storing serialized Java objects. | OTHER | |
VARCHAR Type | Unicode String. | { VARCHAR | LONGVARCHAR | VARCHAR2 | NVARCHAR | NVARCHAR2 | VARCHAR_CASESENSITIVE} [ ( precisionInt ) ] | |
VARCHAR_IGNORECASE Type | Same as VARCHAR, but not case sensitive when comparing. | VARCHAR_IGNORECASE [ ( precisionInt ) ] | |
CHAR Type | This type is supported for compatibility with other databases and older applications. | { CHAR | CHARACTER | NCHAR } [ ( precisionInt ) ] | |
BLOB Type | Like BINARY, but intended for very large values such as files or images. | { BLOB | TINYBLOB | MEDIUMBLOB | LONGBLOB | IMAGE | OID } [ ( precisionInt ) ] | |
CLOB Type | CLOB is like VARCHAR, but intended for very large values. | { CLOB | TINYTEXT | TEXT | MEDIUMTEXT | LONGTEXT | NTEXT | NCLOB } [ ( precisionInt ) ] | |
UUID Type | Universally unique identifier. | UUID | |
ARRAY Type | An array of values. | ARRAY |
Command | Description | SYNTAX | Example |
---|---|---|---|
ALTER INDEX RENAME | Renames an index. | ALTER INDEX indexName RENAME TO newIndexName | |
ALTER SCHEMA RENAME | Renames a schema. | ALTER SCHEMA schema RENAME TO newSchemaName | |
ALTER SEQUENCE | Changes the next value and the increment of a sequence. | ALTER SEQUENCE sequenceName [ RESTART WITH long ] [ INCREMENT BY long ] | |
ALTER TABLE ADD | Adds a new column to a table. | ALTER TABLE tableName ADD name dataType [ DEFAULT expression ] [ [ NOT ] NULL ] [ AUTO_INCREMENT | IDENTITY ] [ BEFORE columnName ] | |
ALTER TABLE ADD CONSTRAINT | Adds a constraint to a table. | ALTER TABLE tableName ADD constraint [ CHECK | NOCHECK ] | |
ALTER TABLE ALTER | Changes the data type of a column, rename a column, change the identity value, or change the selectivity. | ALTER TABLE tableName ALTER COLUMN columnName { { dataType [ DEFAULT expression ] [ [ NOT ] NULL ] [ AUTO_INCREMENT | IDENTITY ] } | { RENAME TO name } | { RESTART WITH long } | { SELECTIVITY int } | { SET DEFAULT expression } | { SET NULL } | { SET NOT NULL } } | |
ALTER TABLE DROP COLUMN | Removes a column from a table. | ALTER TABLE tableName DROP COLUMN columnName | |
ALTER TABLE DROP CONSTRAINT | Removes a constraint or a primary key from a table. | ALTER TABLE tableName DROP { CONSTRAINT [ IF EXISTS ] constraintName | PRIMARY KEY } | |
ALTER TABLE SET | Disables or enables referential integrity checking for a table. | ALTER TABLE tableName SET REFERENTIAL_INTEGRITY { FALSE | TRUE [ CHECK | NOCHECK ] } | |
ALTER TABLE RENAME | Renames a table. | ALTER TABLE tableName RENAME TO newName | |
ALTER USER ADMIN | Switches the admin flag of a user on or off. | ALTER USER userName ADMIN { TRUE | FALSE } | |
ALTER USER RENAME | Renames a user. | ALTER USER userName RENAME TO newUserName | |
ALTER USER SET PASSWORD | Changes the password of a user. | ALTER USER userName SET { PASSWORD string | SALT bytes HASH bytes } | |
ALTER VIEW | Recompiles a view after the underlying tables have been changed or created. | ALTER VIEW viewName RECOMPILE | |
ANALYZE | Updates the selectivity statistics of all tables. | ANALYZE [ SAMPLE_SIZE rowCountInt ] | |
COMMENT | Sets the comment of a database object. | COMMENT ON { { COLUMN [ schemaName. ] tableName.columnName } | { { TABLE | VIEW | CONSTANT | CONSTRAINT | ALIAS | INDEX | ROLE | SCHEMA | SEQUENCE | TRIGGER | USER | DOMAIN } [ schemaName. ] objectName } } IS expression | |
CREATE AGGREGATE | Creates a new user-defined aggregate function. | CREATE AGGREGATE [ IF NOT EXISTS ] newAggregateName FOR className | |
CREATE ALIAS | Creates a new function alias. | CREATE ALIAS [ IF NOT EXISTS ] newFunctionAliasName [ DETERMINISTIC ] { FOR classAndMethodName | AS sourceCodeString } | |
CREATE CONSTANT | Creates a new constant. | CREATE CONSTANT [ IF NOT EXISTS ] newConstantName VALUE expression | |
CREATE DOMAIN | Creates a new data type (domain). | CREATE DOMAIN [ IF NOT EXISTS ] newDomainName AS dataType [ DEFAULT expression ] [ [ NOT ] NULL ] [ SELECTIVITY selectivity ] [ CHECK condition ] | |
CREATE INDEX | Creates a new index. | CREATE { [ UNIQUE ] [ HASH ] INDEX [ IF NOT EXISTS ] newIndexName | PRIMARY KEY [ HASH ] } ON tableName ( indexColumn [,...] ) | |
CREATE LINKED TABLE | Creates a table link to an external table. | CREATE [ [ GLOBAL | LOCAL ] TEMPORARY ] LINKED TABLE [ IF NOT EXISTS ] name ( driverString, urlString, userString, passwordString, [ originalSchemaString, ] originalTableString ) [ EMIT UPDATES | READONLY ] | |
CREATE ROLE | Creates a new role. | CREATE ROLE [ IF NOT EXISTS ] newRoleName | |
CREATE SCHEMA | Creates a new schema. | CREATE SCHEMA [ IF NOT EXISTS ] name [ AUTHORIZATION ownerUserName ] | |
CREATE SEQUENCE | Creates a new sequence. | CREATE SEQUENCE [ IF NOT EXISTS ] newSequenceName [ START WITH long ] [ INCREMENT BY long ] [ CACHE long ] | |
CREATE TABLE | Creates a new table. | CREATE [ CACHED | MEMORY ] [ TEMP | [ GLOBAL | LOCAL ] TEMPORARY ] TABLE [ IF NOT EXISTS ] name { { ( { columnDefinition | constraint } [,...] ) [ AS select ] } | { AS select } } [ ENGINE tableEngineName ] [ TRANSACTIONAL ] [ NOT PERSISTENT ] | |
CREATE TRIGGER | Creates a new trigger. | CREATE TRIGGER [ IF NOT EXISTS ] newTriggerName { BEFORE | AFTER | INSTEAD OF } { INSERT | UPDATE | DELETE | SELECT | ROLLBACK } [,...] ON tableName [ FOR EACH ROW ] [ QUEUE int ] [ NOWAIT ] CALL triggeredClassName | |
CREATE USER | Creates a new user. | CREATE USER [ IF NOT EXISTS ] newUserName { PASSWORD string | SALT bytes HASH bytes } [ ADMIN ] | |
CREATE VIEW | Creates a new view. | CREATE [ OR REPLACE ] [ FORCE ] VIEW [ IF NOT EXISTS ] newViewName [ ( columnName [,...] ) ] AS select | |
DROP AGGREGATE | Drops an existing user-defined aggregate function. | DROP AGGREGATE [ IF EXISTS ] aggregateName | |
DROP ALIAS | Drops an existing function alias. | DROP ALIAS [ IF EXISTS ] existingFunctionAliasName | |
DROP ALL OBJECTS | Drops all existing views, tables, sequences, schemas, function aliases, roles, user-defined aggregate functions, domains, and users (except the current user). | DROP ALL OBJECTS [ DELETE FILES ] | |
DROP CONSTANT | Drops a constant. | DROP CONSTANT [ IF EXISTS ] constantName | |
DROP DOMAIN | Drops a data type (domain). | DROP DOMAIN [ IF EXISTS ] domainName | |
DROP INDEX | Drops an index. | DROP INDEX [ IF EXISTS ] indexName | |
DROP ROLE | Drops a role. | DROP ROLE [ IF EXISTS ] roleName | |
DROP SCHEMA | Drops a schema. | DROP SCHEMA [ IF EXISTS ] schemaName | |
DROP SEQUENCE | Drops a sequence. | DROP SEQUENCE [ IF EXISTS ] sequenceName | |
DROP TABLE | Drops an existing table, or a list of tables. | DROP TABLE [ IF EXISTS ] tableName [,...] [ CASCADE | RESTRICT ] | |
DROP TRIGGER | Drops an existing trigger. | DROP TRIGGER [ IF EXISTS ] triggerName | |
DROP USER | Drops a user. | DROP USER [ IF EXISTS ] userName | |
DROP VIEW | Drops an existing view. | DROP VIEW [ IF EXISTS ] viewName [ RESTRICT | CASCADE ] | |
TRUNCATE TABLE | Removes all rows from a table. | TRUNCATE TABLE tableName |
Command | Description | SYNTAX | Example |
---|---|---|---|
SELECT | Selects data from a table or multiple tables. | SELECT [ TOP term ] [ DISTINCT | ALL ] selectExpression [,...] FROM tableExpression [,...] [ WHERE expression ] [ GROUP BY expression [,...] ] [ HAVING expression ] [ { UNION [ ALL ] | MINUS | EXCEPT | INTERSECT } select ] [ ORDER BY order [,...] ] [ LIMIT expression [ OFFSET expression ] [ SAMPLE_SIZE rowCountInt ] ] [ FOR UPDATE ] | |
INSERT | Inserts a new row / new rows into a table. | INSERT INTO tableName [ ( columnName [,...] ) ] { VALUES { ( { DEFAULT | expression } [,...] ) } [,...] | [ DIRECT ] [ SORTED ] select } | |
UPDATE | Updates data in a table. | UPDATE tableName [ [ AS ] newTableAlias ] SET { columnName= { DEFAULT | expression } } [,...] [ WHERE expression ] | |
DELETE | Deletes rows form a table. | DELETE FROM tableName [ WHERE expression ] | |
BACKUP | Backs up the database files to a . | BACKUP TO fileNameString | |
CALL | Calculates a simple expression. | CALL expression | |
EXPLAIN | Shows the execution plan for a statement. | EXPLAIN { [ PLAN FOR ] | ANALYZE } { select | insert | update | delete | merge } | |
MERGE | Updates existing rows, and insert rows that don't exist. | MERGE INTO tableName [ ( columnName [,...] ) ] [ KEY ( columnName [,...] ) ] { VALUES { ( { DEFAULT | expression } [,...] ) } [,...] | select } | |
RUNSCRIPT | Runs a SQL script from a file. | RUNSCRIPT FROM fileNameString [ scriptCompression ] [ CIPHER cipher PASSWORD string ] [ CHARSET charsetString ] | |
SCRIPT | Creates a SQL script from the database. | SCRIPT [ SIMPLE ] [ NODATA ] [ NOPASSWORDS ] [ NOSETTINGS ] [ DROP ] [ BLOCKSIZE blockSizeInt ] [ TO fileNameString [ scriptCompression ] [ CIPHER cipher PASSWORD string ] ] [ CHARSET charsetString ] | |
SHOW | Lists the schemas, tables, or the columns of a table. | SHOW { SCHEMAS | TABLES [ FROM schemaName ] | COLUMNS FROM tableName [ FROM schemaName ] } |
public insertUser(String name, String email) {
Connection conn = null;
PreparedStatement stmt = null;
try {
conn = setupTheDatabaseConnectionSomehow();
stmt = conn.prepareStatement("INSERT INTO person (name, email) values (?, ?)");
stmt.setString(1, name);
stmt.setString(2, email);
stmt.executeUpdate();
}
finally {
try {
if (stmt != null) { stmt.close(); }
}
catch (Exception e) {
// log this error
}
try {
if (conn != null) { conn.close(); }
}
catch (Exception e) {
// log this error
}
}
}
setInt
method. The PreparedStatement documentation lists all the different methods available for setting and getting data.import java.io.*;
import java.net.*;
import java.util.*;
public class Time_Server_Socket_Test_Java {
public static void main(String[] args) {
try {
Socket s = new Socket(HOST, PORT);//use your own HOST:PORT
try {
InputStream inStream = s.getInputStream();
Scanner in = new Scanner(inStream);
while (in.hasNextLine()) {
String line = in.nextLine();
System.out.println(line);
}
} finally {
s.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
JFrame myFrame = new JFrame();
myFrame.setVisible(true);
myFrame.setExtendedState(myFrame.getExtendedState() | JFrame.MAXIMIZED_BOTH);