django.db.backends.mysql.operations.DatabaseOperations

class documentation

class DatabaseOperations(BaseDatabaseOperations):

Known subclasses: django.contrib.gis.db.backends.mysql.operations.MySQLOperations

Undocumented

Method	`_convert_field_to_tz`	Undocumented
Method	`_prepare_tzname_delta`	Undocumented
Method	`adapt_datetimefield_value`	Transform a datetime value to an object compatible with what is expected by the backend driver for datetime columns.
Method	`adapt_decimalfield_value`	Transform a decimal.Decimal value to an object compatible with what is expected by the backend driver for decimal (numeric) columns.
Method	`adapt_timefield_value`	Transform a time value to an object compatible with what is expected by the backend driver for time columns.
Method	`binary_placeholder_sql`	Some backends require special syntax to insert binary content (MySQL for example uses '_binary %s').
Method	`bulk_insert_sql`	Undocumented
Method	`combine_expression`	No summary
Method	`convert_booleanfield_value`	Undocumented
Method	`convert_datetimefield_value`	Undocumented
Method	`convert_uuidfield_value`	Undocumented
Method	`date_extract_sql`	Given a lookup_type of 'year', 'month', or 'day', return the SQL that extracts a value from the given date field field_name.
Method	`date_trunc_sql`	Given a lookup_type of 'year', 'month', or 'day', return the SQL that truncates the given date or datetime field field_name to a date object with only the given specificity.
Method	`datetime_cast_date_sql`	Return the SQL to cast a datetime value to date value.
Method	`datetime_cast_time_sql`	Return the SQL to cast a datetime value to time value.
Method	`datetime_extract_sql`	Given a lookup_type of 'year', 'month', 'day', 'hour', 'minute', or 'second', return the SQL that extracts a value from the given datetime field field_name.
Method	`datetime_trunc_sql`	Given a lookup_type of 'year', 'month', 'day', 'hour', 'minute', or 'second', return the SQL that truncates the given datetime field field_name to a datetime object with only the given specificity.
Method	`explain_query_prefix`	Undocumented
Method	`fetch_returned_insert_rows`	Given a cursor object that has just performed an INSERT...RETURNING statement into a table, return the tuple of returned data.
Method	`force_no_ordering`	"ORDER BY NULL" prevents MySQL from implicitly ordering by grouped columns. If no ordering would otherwise be applied, we don't want any implicit sorting going on.
Method	`format_for_duration_arithmetic`	Undocumented
Method	`get_db_converters`	Return a list of functions needed to convert field data.
Method	`insert_statement`	Undocumented
Method	`last_executed_query`	Return a string of the query last executed by the given cursor, with placeholders replaced with actual values.
Method	`lookup_cast`	Return the string to use in a query when performing lookups ("contains", "like", etc.). It should contain a '%s' placeholder for the column being searched against.
Method	`max_name_length`	Return the maximum length of table and column names, or None if there is no limit.
Method	`no_limit_value`	Return the value to use for the LIMIT when we are wanting "LIMIT infinity". Return None if the limit clause can be omitted in this case.
Method	`pk_default_value`	Return the value to use during an INSERT statement to specify that the field should use its default value.
Method	`quote_name`	Return a quoted version of the given table, index, or column name. Do not quote the given name if it's already been quoted.
Method	`regex_lookup`	Return the string to use in a query when performing regular expression lookups (using "regex" or "iregex"). It should contain a '%s' placeholder for the column being searched against.
Method	`return_insert_columns`	For backends that support returning columns as part of an insert query, return the SQL and params to append to the INSERT query. The returned fragment should contain a format string to hold the appropriate column.
Method	`sequence_reset_by_name_sql`	Return a list of the SQL statements required to reset sequences passed in `sequences`.
Method	`sql_flush`	Return a list of SQL statements required to remove all data from the given database tables (without actually removing the tables themselves).
Method	`subtract_temporals`	Undocumented
Method	`time_trunc_sql`	Given a lookup_type of 'hour', 'minute' or 'second', return the SQL that truncates the given time or datetime field field_name to a time object with only the given specificity.
Method	`validate_autopk_value`	Certain backends do not accept some values for "serial" fields (for example zero in MySQL). Raise a ValueError if the value is invalid, otherwise return the validated value.
Class Variable	`cast_char_field_without_max_length`	Undocumented
Class Variable	`cast_data_types`	Undocumented
Class Variable	`compiler_module`	Undocumented
Class Variable	`explain_prefix`	Undocumented
Class Variable	`integer_field_ranges`	Undocumented

Inherited from BaseDatabaseOperations:

Constant	`CURRENT_ROW`	Undocumented
Constant	`FOLLOWING`	Undocumented
Constant	`PRECEDING`	Undocumented
Constant	`UNBOUNDED_FOLLOWING`	Undocumented
Constant	`UNBOUNDED_PRECEDING`	Undocumented
Method	`__init__`	Undocumented
Method	`_get_limit_offset_params`	Undocumented
Method	`adapt_datefield_value`	Transform a date value to an object compatible with what is expected by the backend driver for date columns.
Method	`adapt_ipaddressfield_value`	Transform a string representation of an IP address into the expected type for the backend driver.
Method	`adapt_unknown_value`	Transform a value to something compatible with the backend driver.
Method	`autoinc_sql`	Return any SQL needed to support auto-incrementing primary keys, or None if no SQL is necessary.
Method	`bulk_batch_size`	Return the maximum allowed batch size for the backend. The fields are the fields going to be inserted in the batch, the objs contains all the objects to be inserted.
Method	`cache_key_culling_sql`	Return an SQL query that retrieves the first cache key greater than the n smallest.
Method	`check_expression_support`	Check that the backend supports the provided expression.
Method	`combine_duration_expression`	Undocumented
Method	`compiler`	Return the SQLCompiler class corresponding to the given name, in the namespace corresponding to the `compiler_module` attribute on this backend.
Method	`conditional_expression_supported_in_where_clause`	Return True, if the conditional expression is supported in the WHERE clause.
Method	`convert_durationfield_value`	Undocumented
Method	`deferrable_sql`	Return the SQL to make a constraint "initially deferred" during a CREATE TABLE statement.
Method	`distinct_sql`	Return an SQL DISTINCT clause which removes duplicate rows from the result set. If any fields are given, only check the given fields for duplicates.
Method	`end_transaction_sql`	Return the SQL statement required to end a transaction.
Method	`execute_sql_flush`	Execute a list of SQL statements to flush the database.
Method	`fetch_returned_insert_columns`	Given a cursor object that has just performed an INSERT...RETURNING statement into a table, return the newly created data.
Method	`field_cast_sql`	No summary
Method	`for_update_sql`	Return the FOR UPDATE SQL clause to lock rows for an update operation.
Method	`ignore_conflicts_suffix_sql`	Undocumented
Method	`integer_field_range`	Given an integer field internal type (e.g. 'PositiveIntegerField'), return a tuple of the (min_value, max_value) form representing the range of the column type bound to the field.
Method	`last_insert_id`	Given a cursor object that has just performed an INSERT statement into a table that has an auto-incrementing ID, return the newly created ID.
Method	`limit_offset_sql`	Return LIMIT/OFFSET SQL clause.
Method	`max_in_list_size`	Return the maximum number of items that can be passed in a single 'IN' list condition, or None if the backend does not impose a limit.
Method	`modify_insert_params`	Allow modification of insert parameters. Needed for Oracle Spatial backend due to #10888.
Method	`prep_for_like_query`	Prepare a value for use in a LIKE query.
Method	`prepare_sql_script`	Take an SQL script that may contain multiple lines and return a list of statements to feed to successive cursor.execute() calls.
Method	`process_clob`	Return the value of a CLOB column, for backends that return a locator object that requires additional processing.
Method	`savepoint_commit_sql`	Return the SQL for committing the given savepoint.
Method	`savepoint_create_sql`	Return the SQL for starting a new savepoint. Only required if the "uses_savepoints" feature is True. The "sid" parameter is a string for the savepoint id.
Method	`savepoint_rollback_sql`	Return the SQL for rolling back the given savepoint.
Method	`sequence_reset_sql`	Return a list of the SQL statements required to reset sequences for the given models.
Method	`set_time_zone_sql`	Return the SQL that will set the connection's time zone.
Method	`start_transaction_sql`	Return the SQL statement required to start a transaction.
Method	`tablespace_sql`	Return the SQL that will be used in a query to define the tablespace.
Method	`time_extract_sql`	Given a lookup_type of 'hour', 'minute', or 'second', return the SQL that extracts a value from the given time field field_name.
Method	`unification_cast_sql`	Given a field instance, return the SQL that casts the result of a union to that type. The resulting string should contain a '%s' placeholder for the expression being cast.
Method	`window_frame_end`	Undocumented
Method	`window_frame_range_start_end`	Undocumented
Method	`window_frame_rows_start_end`	Return SQL for start and end points in an OVER clause window frame.
Method	`window_frame_start`	Undocumented
Method	`year_lookup_bounds_for_date_field`	Return a two-elements list with the lower and upper bound to be used with a BETWEEN operator to query a DateField value using a year lookup.
Method	`year_lookup_bounds_for_datetime_field`	Return a two-elements list with the lower and upper bound to be used with a BETWEEN operator to query a DateTimeField value using a year lookup.
Class Variable	`set_operators`	Undocumented
Instance Variable	`_cache`	Undocumented
Instance Variable	`connection`	Undocumented

def _convert_field_to_tz(self, field_name, tzname):

Undocumented

def _prepare_tzname_delta(self, tzname):

Undocumented

def adapt_datetimefield_value(self, value):

overrides django.db.backends.base.operations.BaseDatabaseOperations.adapt_datetimefield_value

Transform a datetime value to an object compatible with what is expected by the backend driver for datetime columns.

def adapt_decimalfield_value(self, value, max_digits=None, decimal_places=None):

overrides django.db.backends.base.operations.BaseDatabaseOperations.adapt_decimalfield_value

Transform a decimal.Decimal value to an object compatible with what is expected by the backend driver for decimal (numeric) columns.

def adapt_timefield_value(self, value):

overrides django.db.backends.base.operations.BaseDatabaseOperations.adapt_timefield_value

Transform a time value to an object compatible with what is expected by the backend driver for time columns.

def binary_placeholder_sql(self, value):

overrides django.db.backends.base.operations.BaseDatabaseOperations.binary_placeholder_sql

Some backends require special syntax to insert binary content (MySQL for example uses '_binary %s').

def bulk_insert_sql(self, fields, placeholder_rows):

Undocumented

def combine_expression(self, connector, sub_expressions):

overrides django.db.backends.base.operations.BaseDatabaseOperations.combine_expression

Combine a list of subexpressions into a single expression, using the provided connecting operator. This is required because operators can vary between backends (e.g., Oracle with %% and &) and between subexpression types (e.g., date expressions).

def convert_booleanfield_value(self, value, expression, connection):

Undocumented

def convert_datetimefield_value(self, value, expression, connection):

Undocumented

def convert_uuidfield_value(self, value, expression, connection):

Undocumented

def date_extract_sql(self, lookup_type, field_name):

overrides django.db.backends.base.operations.BaseDatabaseOperations.date_extract_sql

Given a lookup_type of 'year', 'month', or 'day', return the SQL that extracts a value from the given date field field_name.

def date_trunc_sql(self, lookup_type, field_name, tzname=None):

overrides django.db.backends.base.operations.BaseDatabaseOperations.date_trunc_sql

Given a lookup_type of 'year', 'month', or 'day', return the SQL that truncates the given date or datetime field field_name to a date object with only the given specificity.

If tzname is provided, the given value is truncated in a specific timezone.

def datetime_cast_date_sql(self, field_name, tzname):

overrides django.db.backends.base.operations.BaseDatabaseOperations.datetime_cast_date_sql

Return the SQL to cast a datetime value to date value.

def datetime_cast_time_sql(self, field_name, tzname):

overrides django.db.backends.base.operations.BaseDatabaseOperations.datetime_cast_time_sql

Return the SQL to cast a datetime value to time value.

def datetime_extract_sql(self, lookup_type, field_name, tzname):

overrides django.db.backends.base.operations.BaseDatabaseOperations.datetime_extract_sql

Given a lookup_type of 'year', 'month', 'day', 'hour', 'minute', or 'second', return the SQL that extracts a value from the given datetime field field_name.

def datetime_trunc_sql(self, lookup_type, field_name, tzname):

overrides django.db.backends.base.operations.BaseDatabaseOperations.datetime_trunc_sql

Given a lookup_type of 'year', 'month', 'day', 'hour', 'minute', or 'second', return the SQL that truncates the given datetime field field_name to a datetime object with only the given specificity.

def explain_query_prefix(self, format=None, **options):

overrides django.db.backends.base.operations.BaseDatabaseOperations.explain_query_prefix

Undocumented

def fetch_returned_insert_rows(self, cursor):

Given a cursor object that has just performed an INSERT...RETURNING statement into a table, return the tuple of returned data.

def force_no_ordering(self):

overrides django.db.backends.base.operations.BaseDatabaseOperations.force_no_ordering

"ORDER BY NULL" prevents MySQL from implicitly ordering by grouped columns. If no ordering would otherwise be applied, we don't want any implicit sorting going on.

def format_for_duration_arithmetic(self, sql):

Undocumented

def get_db_converters(self, expression):

overrides django.db.backends.base.operations.BaseDatabaseOperations.get_db_converters

Return a list of functions needed to convert field data.

Some field types on some backends do not provide data in the correct format, this is the hook for converter functions.

def insert_statement(self, ignore_conflicts=False):

overrides django.db.backends.base.operations.BaseDatabaseOperations.insert_statement

Undocumented

def last_executed_query(self, cursor, sql, params):

overrides django.db.backends.base.operations.BaseDatabaseOperations.last_executed_query

Return a string of the query last executed by the given cursor, with placeholders replaced with actual values.

sql is the raw query containing placeholders and params is the sequence of parameters. These are used by default, but this method exists for database backends to provide a better implementation according to their own quoting schemes.

def lookup_cast(self, lookup_type, internal_type=None):

overrides django.db.backends.base.operations.BaseDatabaseOperations.lookup_cast

Return the string to use in a query when performing lookups ("contains", "like", etc.). It should contain a '%s' placeholder for the column being searched against.

def max_name_length(self):

overrides django.db.backends.base.operations.BaseDatabaseOperations.max_name_length

Return the maximum length of table and column names, or None if there is no limit.

def no_limit_value(self):

overrides django.db.backends.base.operations.BaseDatabaseOperations.no_limit_value

Return the value to use for the LIMIT when we are wanting "LIMIT infinity". Return None if the limit clause can be omitted in this case.

def pk_default_value(self):

overrides django.db.backends.base.operations.BaseDatabaseOperations.pk_default_value

Return the value to use during an INSERT statement to specify that the field should use its default value.

def quote_name(self, name):

overrides django.db.backends.base.operations.BaseDatabaseOperations.quote_name

Return a quoted version of the given table, index, or column name. Do not quote the given name if it's already been quoted.

def regex_lookup(self, lookup_type):

overrides django.db.backends.base.operations.BaseDatabaseOperations.regex_lookup

Return the string to use in a query when performing regular expression lookups (using "regex" or "iregex"). It should contain a '%s' placeholder for the column being searched against.

If the feature is not supported (or part of it is not supported), raise NotImplementedError.

def return_insert_columns(self, fields):

overrides django.db.backends.base.operations.BaseDatabaseOperations.return_insert_columns

For backends that support returning columns as part of an insert query, return the SQL and params to append to the INSERT query. The returned fragment should contain a format string to hold the appropriate column.

def sequence_reset_by_name_sql(self, style, sequences):

overrides django.db.backends.base.operations.BaseDatabaseOperations.sequence_reset_by_name_sql

Return a list of the SQL statements required to reset sequences passed in sequences.

The style argument is a Style object as returned by either color_style() or no_style() in django.core.management.color.

def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):

overrides django.db.backends.base.operations.BaseDatabaseOperations.sql_flush

Return a list of SQL statements required to remove all data from the given database tables (without actually removing the tables themselves).

The style argument is a Style object as returned by either color_style() or no_style() in django.core.management.color.

If reset_sequences is True, the list includes SQL statements required to reset the sequences.

The allow_cascade argument determines whether truncation may cascade to tables with foreign keys pointing the tables being truncated. PostgreSQL requires a cascade even if these tables are empty.

def subtract_temporals(self, internal_type, lhs, rhs):

overrides django.db.backends.base.operations.BaseDatabaseOperations.subtract_temporals

Undocumented

def time_trunc_sql(self, lookup_type, field_name, tzname=None):

overrides django.db.backends.base.operations.BaseDatabaseOperations.time_trunc_sql

Given a lookup_type of 'hour', 'minute' or 'second', return the SQL that truncates the given time or datetime field field_name to a time object with only the given specificity.

If tzname is provided, the given value is truncated in a specific timezone.

def validate_autopk_value(self, value):

overrides django.db.backends.base.operations.BaseDatabaseOperations.validate_autopk_value

Certain backends do not accept some values for "serial" fields (for example zero in MySQL). Raise a ValueError if the value is invalid, otherwise return the validated value.

cast_char_field_without_max_length: str =

overrides django.db.backends.base.operations.BaseDatabaseOperations.cast_char_field_without_max_length

Undocumented

cast_data_types: dict[str, str] =

overrides django.db.backends.base.operations.BaseDatabaseOperations.cast_data_types

Undocumented

compiler_module: str =

overrides django.db.backends.base.operations.BaseDatabaseOperations.compiler_module

Undocumented

explain_prefix: str =

overrides django.db.backends.base.operations.BaseDatabaseOperations.explain_prefix

Undocumented

integer_field_ranges =

overrides django.db.backends.base.operations.BaseDatabaseOperations.integer_field_ranges

Undocumented