WebSQL Server - WebSQL Reference

WebSQL Reference

WebSQL is a SQL enhancement and unification to generalize access to increasingly heterogeneous data in mixed databases: relational and non-relational. WebSQL does not replace a SQL supported by a specific database, but adds missing functionality.

WebSQL consists of the following statements:

SELECT

The SELECT statement is used to retrieve data from a database where the SELECT clause allows specifying values (aka columns/properties/attributes) to be returned in the result output and its JSON format: Array (default) or Map.

SELECT ( * | expr [, ...]) FROM 
    [ WHERE ]
    [ ORDER BY order [, ...]]
    [ LIMIT number ]

// where:

path: value_name [. value_name ...]

expr: [ path .] value_name [. * | [ AS ] alias ]  

order: path [ ASC | DESC ]

FROM

The FROM clause allows specifying data sources: tables, etc.

FROM expr [, ...]

// where:

expr: table_name [[ AS ] from_alias ]

WHERE

The WHERE clause allows specifying the search condition.

WHERE cond [( AND | OR ) ...]

// where:
            
cond: [ from_alias. ] value_name is null
cond: [ from_alias. ] value_name is not null
cond: [ from_alias. ] value_name oper ( const | var )
cond: [ from_alias. ] value_name oper [ from_alias. ] value_name
oper: = | != | <> | >= | > | <= | <

INSERT

The INSERT statement is used to add data into a database. WebSQL supports the following syntaxes:

INSERT table_name { json } 

// a sample with json:

INSERT Test {
    "aNumber"  : 123,
    "aString"  : "test",
    "aBoolean" : true,
    "aNull"    : null,
    "anArray"  : [ ... ],
    "anObject" : { ... }  
}

REPLACE

The REPLACE statement is used to replace data in a database. WebSQL supports the following syntaxes:

REPLACE table_name WHERE clause { json }

// a sample with json:

REPLACE Test WHERE aNumber = 123 {
    "aString"  : "test",
    "aBoolean" : true,
    "aNull"    : null,
    "anArray"  : [ ... ],
    "anObject" : { ... }   
}

UPDATE

The UPDATE statement is used to update data in a database. WebSQL supports the following syntaxes:

UPDATE table_name WHERE clause { json }

// a sample with json:

UPDATE Test WHERE aNumber = 123 {
    "aString"  : "test",
    "aBoolean" : true,
    "aNull"    : null,
    "anArray"  : [ ... ],
    "anObject" : { ... }   
}

DELETE

The DELETE statement is used to delete data from a database. WebSQL supports the following syntaxes:

DELETE table_name WHERE clause