Javascript Query Language supports a handful of built-in data types for all sorts of data, strings, numbers, dates, even executable functions. The default dataType, for tables that do not specify datatypes for their columns, is "AMBI", which stores strings, numbers, functions and Date objects, anything else is converted to a string.

jSQL does provide an API for adding your own data type definitions, which is useful for storing instances of your own custom objects.

• NUMERIC(M)
  • Aliases: NUMBER, DECIMAL, FLOAT
  • Stores types as numbers
  • The optionalM represents the display width of the number
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the display width is for application use only and does not restrict the length of the value stored in the column.
• TINYINT(M)
  • Store an integer between -128 and 127
  • The optionalM represents the display width of the number
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the display width is for application use only and does not restrict the length of the value
• SMALLINT(M)
  • Store an integer between -32768 and 32767
  • The optionalM represents the display width of the number
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the display width is for application use only and does not restrict the length of the value
• MEDIUMINT(M)
  • Store an integer between -8388608 and 8388607
  • The optionalM represents the display width of the number
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the display width is for application use only and does not restrict the length of the value
• INT(M)
  • Store an integer between -2147483648 and 2147483647
  • The optionalM represents the display width of the number
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the display width is for application use only and does not restrict the length of the value
• BIGINT(M)
  • Store an integer between -9007199254740991 and 9007199254740991
  • The optionalM represents the display width of the number
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the display width is for application use only and does not restrict the length of the value

• VARCHAR(M)
  • Store an string of varying length
  • The optionalM represents the length of the string
  • The perens are optional too if you are not providing an argument forM
  • As in MySQL, the length is for application use only and does not restrict the length of the value
• CHAR(M)
  • Stores a string of a fixed length
  • TheM represents the length of the string
  • If string is shorter thanM, string is right padded with spaces, if string is longer, it is truncated.
• ENUM(M,N, ...)
  • Stores any of the pre-specified strings
  • M,N, and any other arguments you pass to it will be available for insert in that column. Anything else will throw an error.

• FUNCTION
  • Stores functions.
  • Will throw an error if non functions are stored.
  • Must use a prepared statement to insert a function into a table.
• BOOLEAN
  • Alias: BOOL
  • Store boolean values
• JSON
  • Stores a JSON object
  • Must use a prepared statement to insert a JSON object (or Array) into a table
• DATE
  • Stores a JavascriptDate object
  • If using a prepared statement, you can insert an actual JS date object, otherwise any quoted string parsable byDate.parse() will work.
• AMBI
  • Stores functions and JS Date objects, everything else is converted to a string.

Custom datatypes are useful for storing instances of custom objects, or otherwise filtering your data in your columns.

To create a new data type, use thejSQL.types.add() method to add a new dataType. It takes an object with 4 properties:

• type: The datatype name
• aliases: An array of aliases (alternative names for this datatype)
• serialize: A function that receives the value to be stored, and an array containing any arguments passed into the table definition. This function must return a string serialization of the object.
• unserialize: A function that takes the serialized value to be returned and any arguments passed from the table definition and should return the unserialized version of the stored object.

When using custom data types, it is important to defin them before the database is loaded into memory (beforejSQL.load() is called), so that any items stored in memory can be properly interpreted by the API.

jSQL.types.add({type: "ENUM",serialize: function(value, args){    if(args.indexOf(value) < -1) value = args[0];    return value;},unserialize: function(value, args){return value;}});