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DOUBLE literals: |br| [E|e [plus-sign | minus-sign] digit ...] |br| Examples: 1E5, 1.1E5. |br| A literal has :ref:`data type = DOUBLE <sql_data_type_double>` if it contains "E". DOUBLE literals are also known as floating-point literals or approximate-numeric literals. To represent "Inf" (infinity), write a real numeric outside the double-precision numeric range, for example 1E309. To represent "nan" (not a number), write an expression that does not result in a real numeric, for example 0/0, using Tarantool/NoSQL. This will appear as NULL in Tarantool/SQL. In an earlier version literals containing periods were considered to be :ref:`NUMBER <sql_data_type_number>` literals. In a future version "nan" may not appear as NULL. Prior to Tarantool :tarantool-release:`2.10.0`, digits with periods such as .0 were considered to be DOUBLE literals, but now they are considered to be DECIMAL literals.
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Expressions, for example ``a + b`` or ``a > b AND NOT a <= b``, may have arithmetic operators ``+ - / *``, may have comparison operators ``= > < <= >= LIKE``, and may be combined with ``AND OR NOT``, with optional parentheses.
Выражения, например ``a + b`` или ``a > b AND NOT a <= b``, могут содержать арифметические операторы ``+ - / *`` и операторы сравнения ``= > < <= >= LIKE``, а также могут использоваться вместе с ``AND OR NOT``, при этом круглые скобки необязательны.
Concepts
 
In the :ref:`SQL beginners' guide <sql_beginners_guide>` there was discussion of: |br| What are: relational databases, tables, views, rows, and columns? |br| What are: transactions, write-ahead logs, commits and rollbacks? |br| What are: security considerations? |br| How to: add, delete, or update rows in tables? |br| How to: work inside transactions with commits and/or rollbacks? |br| How to: select, join, filter, group, and sort rows?
 
Tarantool has a "schema". A schema is a container for all database objects. A schema may be called a "database" in other DBMS implementations
 
Tarantool allows four types of "database objects" to be created within the schema: tables, triggers, indexes, and constraints. Within tables, there are "columns".
 
Almost all Tarantool SQL statements begin with a reserved-word "verb" such as INSERT, and end optionally with a semicolon. For example: ``INSERT INTO t VALUES (1);``
 
A Tarantool SQL database and a Tarantool NoSQL database are the same thing. However, some operations are only possible with SQL, and others are only possible with NoSQL. Mixing SQL statements with NoSQL requests is allowed.
 
Tokens
 
The token is the minimum SQL-syntax unit that Tarantool understands. These are the types of tokens:
 
Keywords -- official words in the language, for example ``SELECT`` |br| Literals -- constants for numerics or strings, for example ``15.7`` or ``'Taranto'`` |br| Identifiers -- for example column55 or table_of_accounts |br| Operators (strictly speaking "non-alphabetic operators") -- for example ``* / + - ( ) , ; < = >=``
Ключевые слова --- официальные слова языка, например ``SELECT``. |br| Литералы --- числовые или строковые константы, например ``15.7`` или ``'Taranto'``. |br| Идентификаторы --- имена объектов, например ``column55`` или ``table_of_accounts``. |br| Операторы (строго говоря, неалфавитные операторы) --- математические операторы, например ``* / + - ( ) , ; < = >=``.
Tokens can be separated from each other by one or more separators: |br| * White space characters: tab (U+0009), line feed (U+000A), vertical tab (U+000B), form feed (U+000C), carriage return (U+000D), space (U+0020), next line (U+0085), and all the rare characters in Unicode classes Zl and Zp and Zs. For a full list see https://github.com/tarantool/tarantool/issues/2371. |br| * Bracketed comments (beginning with ``/*`` and ending with ``*/``) |br| * Simple comments (beginning with ``--`` and ending with line feed) |br| Separators are not necessary before or after operators. |br| Separators are necessary after keywords or numerics or ordinary identifiers, unless the following token is an operator. |br| Thus Tarantool can understand this series of six tokens: |br| ``SELECT'a'FROM/**/t;`` |br| but for readability one would usually use spaces to separate tokens: |br| ``SELECT 'a' FROM /**/ t;``
Токены могут быть отделены друг от друга одним или несколькими разделителями. |br| * Символы-разделители: табуляция (U+0009), перевод строки (U+000A), вертикальная табуляция (U+000B), смена страницы (U+000C), возврат каретки (U+000D), пробел (U+0020), следующая строка (U+0085), а также все редкие символы классов Zl, Zp и Zs Юникода. Полный список символов вы найдете на странице https://github.com/tarantool/tarantool/issues/2371. |br| * Комментарии (начинаются с ``/*`` и заканчиваются ``*/``). |br| * Однострочные комментарии (начинаются с ``--`` и заканчиваются переводом строки). |br| Разделители не нужны ни перед операторами, ни после них. |br| Разделители необходимы после ключевых слов, числовых значений или обычных идентификаторов, если только следующий токен не является оператором. |br| Таким образом, Tarantool может понять следующую серию из шести токенов: |br| ``SELECT'a'FROM/**/t;`` |br| Но для удобства чтения токены обычно разделяют пробелами: |br| ``SELECT 'a' FROM /**/ t;``
Literals
 
There are eight kinds of literals: BOOLEAN INTEGER DOUBLE DECIMAL STRING VARBINARY MAP ARRAY.
 
BOOLEAN literals: |br| TRUE | FALSE | UNKNOWN |br| A literal has :ref:`data type = BOOLEAN <sql_data_type_boolean>` if it is the keyword TRUE or FALSE. UNKNOWN is a synonym for NULL. A literal may have type = BOOLEAN if it is the keyword NULL and there is no context to indicate a different data type.
 
INTEGER literals: |br| [plus-sign | minus-sign] digit [digit ...] |br| or, for a hexadecimal integer literal, |br| [plus-sign | minus-sign] 0X | 0x hexadecimal-digit [hexadecimal-digit ...] |br| Examples: 5, -5, +5, 55555, 0X55, 0x55 |br| Hexadecimal 0X55 is equal to decimal 85. A literal has :ref:`data type = INTEGER <sql_data_type_integer>` if it contains only digits and is in the range -9223372036854775808 to +18446744073709551615, integers outside that range are illegal.
 
DOUBLE literals: |br| [E|e [plus-sign | minus-sign] digit ...] |br| Examples: 1E5, 1.1E5. |br| A literal has :ref:`data type = DOUBLE <sql_data_type_double>` if it contains "E". DOUBLE literals are also known as floating-point literals or approximate-numeric literals. To represent "Inf" (infinity), write a real numeric outside the double-precision numeric range, for example 1E309. To represent "nan" (not a number), write an expression that does not result in a real numeric, for example 0/0, using Tarantool/NoSQL. This will appear as NULL in Tarantool/SQL. In an earlier version literals containing periods were considered to be :ref:`NUMBER <sql_data_type_number>` literals. In a future version "nan" may not appear as NULL. Prior to Tarantool :tarantool-release:`2.10.0`, digits with periods such as .0 were considered to be DOUBLE literals, but now they are considered to be DECIMAL literals.
DOUBLE: |br| [+ | -] [цифра [цифра ...]] точка [цифра [цифра ...]] |br| [E|e [+ | -] цифра ...] |br| Примеры: ``.0``, ``1.0``, ``1E5``, ``1.1E5``. Значение имеет :ref:`тип данных DOUBLE <sql_data_type_double>`, если оно содержит десятичную точку или "E". Значения типа DOUBLE также известны как значения с плавающей точкой или приблизительные числа. Чтобы представить значение "Inf" (бесконечность), запишите вещественное число вне диапазона double, например, ``1E309``. Чтобы представить "NaN" (Not a Number, нечисловое значение), напишите с помощью Tarantool/NoSQL выражение, результат которого не является вещественным числом, например ``0/0``. В Tarantool/SQL результат будет отображаться как ``NULL``. В предыдущих версиях значения, содержащие десятичную точку, считались значениями типа :ref:`NUMBER <sql_data_type_number>`. В будущем "NaN" может не отображаться как ``NULL``.
DECIMAL literals: |br| [plus-sign | minus-sign] [digit [digit ...]] period [digit [digit ...]] |br| Examples: .0, 1.0, 12345678901234567890.123456789012345678 |br| A literal has :ref:`data type = DECIMAL <sql_data_type_decimal>` if it contains a period, and does not contain "E". DECIMAL literals may contain up to 38 digits; if there are more, then post-decimal digits may be subject to rounding. In earlier Tarantool versions literals containing periods were considered to be :ref:`NUMBER <sql_data_type_number>` or :ref:`DECIMAL <sql_data_type_double>` literals.
 
STRING literals: |br| [quote] [character ...] [quote] |br| Examples: ``'ABC'``, ``'AB''C'`` |br| A literal has :ref:`data type type = STRING <sql_data_type_string>` if it is a sequence of zero or more characters enclosed in single quotes. The sequence ``''`` (two single quotes in a row) is treated as ``'`` (a single quote) when enclosed in quotes, that is, ``'A''B'`` is interpreted as ``A'B``.
 
VARBINARY literals: |br| X|x [quote] [hexadecimal-digit-pair ...] [quote] |br| Example: ``X'414243'``, which will be displayed as ``'ABC'``. |br| A literal has :ref:`data type = VARBINARY <sql_data_type_varbinary>` ("variable-length binary") if it is the letter X followed by quotes containing pairs of hexadecimal digits, representing byte values.
 
MAP literals: |br| [left curly bracket] key [colon] value [right curly bracket] |br| Examples: ``{'a':1}``, ``{1:'a'}`` |br| A map literal is a pair of curly brackets (also called "braces") enclosing a STRING or INTEGER or UUID literal (called the map "key") followed by a colon followed by any type of literal (called the map "value"). This is a minimal form of a :ref:`MAP expression <sql_map_expression>`.
 
ARRAY literals: |br| [left square bracket] [literal] [right square bracket] |br| Examples: ``[1]``, ``['a']`` |br| An ARRAY literal is a literal value which is enclosed inside square brackets. This is a minimal form of an :ref:`ARRAY expression <sql_array_expression>`.
 
Here are four ways to put non-ASCII characters,such as the Greek letter α alpha, in string literals: |br| First make sure that your shell program is set to accept characters as UTF-8. A simple way to check is |br| ``SELECT hex(cast('α' as VARBINARY));`` If the result is CEB1 -- which is the hexadecimal value for the UTF-8 representation of α -- it is good. |br|
 
(1) Simply enclose the character inside ``'...'``, |br| ``'α'``
 
(2) Find out what is the hexadecimal code for the UTF-8 representation of α, and enclose that inside ``X'...'``, then cast to STRING because ``X'...'`` literals are data type VARBINARY not STRING, |br| ``CAST(X'CEB1' AS STRING)`` |br|
 
(3) Find out what is the Unicode code point for α, and pass that to the :ref:`CHAR function <sql_function_char>`. |br| ``CHAR(945) /* remember that this is α as data type STRING not VARBINARY */`` |br|
 
(4) Enclose statements inside double quotes and include Lua escapes, for example ``box.execute("SELECT '\206\177';")`` |br|
 
One can use the concatenation operator ``||`` to combine characters made with any of these methods.
 
Limitations: (`Issue#2344 <https://github.com/tarantool/tarantool/issues/2344>`_) |br| * ``LENGTH('A''B') = 3`` which is correct, but on the Tarantool console the display from ``SELECT A''B;`` is ``A''B``, which is misleading. |br| * It is unfortunate that ``X'41'`` is a byte sequence which looks the same as ``'A'``, but it is not the same. ``box.execute("select 'A' < X'41';")`` is not legal at the moment. This happens because ``TYPEOF(X'41')`` yields ``'varbinary'``. Also it is illegal to say ``UPDATE ... SET string_column = X'41'``, one must say ``UPDATE ... SET string_column = CAST(X'41' AS STRING);``. |br|
Ограничения (подробнее в `Issue#2344 на GitHub <https://github.com/tarantool/tarantool/issues/2344>`_): |br| * Инструкции, подобные ``LENGTH('A''B') = 3``, корректны, но в консоли Tarantool при выполнении ``SELECT A''B;`` будет выведено ``A''B``, что вводит в заблуждение. |br| * Хотя последовательность байтов ``X'41'`` выглядит так же, как ``'A'``, но это не одно и то же. Инструкции, подобные ``box.execute("select 'A' < X'41';")``, в настоящее время недопустимы, поскольку ``TYPEOF(X'41')`` возвращает ``'varbinary'``. Также нельзя выполнить ``UPDATE ... SET string_column = X'41'``; правильным вариантом будет ``UPDATE ... SET string_column = CAST(X'41' AS STRING);``. |br| * Не принято говорить, что типом данных DOUBLE обладает любое числовое значение, содержащее десятичную точку.
Identifiers
 
All database objects -- tables, triggers, indexes, columns, constraints, functions, collations -- have identifiers. An identifier should begin with a letter or underscore (``'_'``) and should contain only letters, digits, dollar signs (``'$'``), or underscores. The maximum number of bytes in an identifier is between 64982 and 65000. For compatibility reasons, Tarantool recommends that an identifier should not have more than 30 characters.
 
Letters in identifiers do not have to come from the Latin alphabet, for example the Japanese syllabic ひ and the Cyrillic letter д are legal. But be aware that a Latin letter needs only one byte but a Cyrillic letter needs two bytes, so Cyrillic identifiers consume a tiny amount more space.
 

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testing_project / Documentation: reference/reference_sql/sql_user_guide — Russian

DOUBLE literals: |br| [E|e [plus-sign | minus-sign] digit ...] |br| Examples: 1E5, 1.1E5. |br| A literal has :ref:`data type = DOUBLE <sql_data_type_double>` if it contains "E". DOUBLE literals are also known as floating-point literals or approximate-numeric literals. To represent "Inf" (infinity), write a real numeric outside the double-precision numeric range, for example 1E309. To represent "nan" (not a number), write an expression that does not result in a real numeric, for example 0/0, using Tarantool/NoSQL. This will appear as NULL in Tarantool/SQL. In an earlier version literals containing periods were considered to be :ref:`NUMBER <sql_data_type_number>` literals. In a future version "nan" may not appear as NULL. Prior to Tarantool :tarantool-release:`2.10.0`, digits with periods such as .0 were considered to be DOUBLE literals, but now they are considered to be DECIMAL literals.
DOUBLE: |br| [+ | -] [цифра [цифра ...]] точка [цифра [цифра ...]] |br| [E|e [+ | -] цифра ...] |br| Примеры: ``.0``, ``1.0``, ``1E5``, ``1.1E5``. Значение имеет :ref:`тип данных DOUBLE <sql_data_type_double>`, если оно содержит десятичную точку или "E". Значения типа DOUBLE также известны как значения с плавающей точкой или приблизительные числа. Чтобы представить значение "Inf" (бесконечность), запишите вещественное число вне диапазона double, например, ``1E309``. Чтобы представить "NaN" (Not a Number, нечисловое значение), напишите с помощью Tarantool/NoSQL выражение, результат которого не является вещественным числом, например ``0/0``. В Tarantool/SQL результат будет отображаться как ``NULL``. В предыдущих версиях значения, содержащие десятичную точку, считались значениями типа :ref:`NUMBER <sql_data_type_number>`. В будущем "NaN" может не отображаться как ``NULL``.
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