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box.execute() | Tarantool
 

Версия:

box.execute()

box.execute()

box.execute(sql-statement[, extra-parameters])

Execute the SQL statement contained in the sql-statement parameter.

Параметры:
возвращает:

depends on statement

There are two ways to pass extra parameters for box.execute():

  • The first way, which is the preferred way, is to put placeholders in the string, and pass a second argument, an extra-parameters table. A placeholder is either a question mark «?», or a colon «:» followed by a name. An extra parameter is any Lua expression. If placeholders are question marks, then they will be replaced by extra-parameter values in corresponding positions, that is, the first ? will be replaced by the first extra parameter, the second ? will be replaced by the second extra parameter, and so on. If placeholders are :names, then they will be replaced by extra-parameter values with corresponding names. For example this request which contains literal values 1 and „x“:
    box.execute([[INSERT INTO tt VALUES (1, 'x');]]);
    is the same as this request which contains two question-mark placeholders (? and ?) and a two-element extra-parameters table:
    x = {1,'x'}
    box.execute([[INSERT INTO tt VALUES (?, ?);]], x);
    and is the same as this request which contains two :name placeholders (:a and :b) and a two-element extra-parameters table with elements named «a» and «b»:
    box.execute([[INSERT INTO tt VALUES (:a, :b);]], {{[':a']=1},{[':b']='x'}})
  • The second way is to concatenate strings. For example, this Lua script will insert 10 rows with different primary-key values into table t:
    for i=1,10,1 do
        box.execute("insert into t values (" .. i .. ")")
    end
    When creating SQL statements based on user input, application developers should beware of SQL injection.

Since box.execute() is an invocation of a Lua function, it either causes an error message or returns a value.

For some statements the returned value will contain a field named «rowcount». For example;

tarantool> box.execute([[CREATE TABLE table1 (column1 INT PRIMARY key, column2 VARCHAR(10));]])
---
- rowcount: 1
...
tarantool> box.execute([[INSERT INTO table1 VALUES (55,'Hello SQL world!');]])
---
- rowcount: 1
...

For statements that cause generation of values for PRIMARY KEY AUTOINCREMENT columns, there will also be a field named «autoincrement_ids».

For SELECT or PRAGMA statements, the returned value will be a result set, containing a field named «metadata» (a table with column names and Tarantool/NoSQL type names) and a field named «rows» (a table with the contents of each row).

For example, for a statement SELECT "x" FROM t WHERE "x"=5; where "x" is an INTEGER column and there is one row, a display on the Tarantool client will look like this:

tarantool> box.execute([[SELECT "x" FROM t WHERE "x"=5;]])
---
- metadata:
  - name: x
    type: integer
  rows:
  - [5]
...

For a look at raw format of SELECT results, see Binary protocol – responses for SQL.

The order of components within a map is not guaranteed.

If sql_full_metadata in the _session_settings system table is TRUE, then result set metadata may include these things in addition to name and type:

  • collation (present only if COLLATE clause is specified for a STRING) = «Collation».
  • is_nullable (present only if the select list specified a base table column and nothing else) = false if column was defined as NOT NULL, otherwise true. If this is not present, that implies that nullability is unknown.
  • is_autoincrement (present only if the select list specified a base table column and nothing else) = true if column was defined as PRIMARY KEY AUTOINCREMENT, otherwise false.
  • span (always present) = the original expression in a select list, which will often be the same as name if the select list specifies a column name and nothing else, but otherwise will differ, for example after SELECT x+55 AS x FROM t; the name is X and the span is x+55. If span and name are the same then the content is MP_NIL.

Alternative: if you are using the Tarantool server as a client, you can switch languages thus:

\set language sql
\set delimiter ;

Afterwards, you can enter any SQL statement directly without needing box.execute().

There is also an execute() function available via module net.box, for example after conn = net_box.connect(url-string) one can say conn:execute(sql-statement]).