Package org.apache.calcite.sql.validate

Interface SqlConformance

All Known Implementing Classes:

SqlAbstractConformance, SqlConformanceEnum, SqlDelegatingConformance

public interface SqlConformance

Enumeration of valid SQL compatibility modes.

For most purposes, one of the built-in compatibility modes in enum SqlConformanceEnum will suffice.

If you wish to implement this interface to build your own conformance, we strongly recommend that you extend SqlAbstractConformance, or use a SqlDelegatingConformance, so that you won't be broken by future changes.

See Also:

• SqlConformanceEnum
• SqlAbstractConformance
• SqlDelegatingConformance

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static enum	SqlConformance.SelectAliasLookup	Value describing how to perform lookup for aliases defined in a SELECT list.

Field Summary

Fields

Modifier and Type	Field	Description
static final SqlConformanceEnum	DEFAULT	Deprecated.
static final SqlConformanceEnum	ORACLE_10	Deprecated.
static final SqlConformanceEnum	PRAGMATIC_2003	Deprecated.
static final SqlConformanceEnum	PRAGMATIC_99	Deprecated.
static final SqlConformanceEnum	STRICT_2003	Deprecated.
static final SqlConformanceEnum	STRICT_92	Deprecated.
static final SqlConformanceEnum	STRICT_99	Deprecated.

Method Summary

Modifier and Type	Method	Description
boolean	allowAliasUnnestItems()	Whether directly alias array items in UNNEST.
boolean	allowCharLiteralAlias()	Whether this dialect allows character literals as column aliases.
boolean	allowExplicitRowValueConstructor()	Whether to allow SQL syntax "ROW(expr1, expr2, expr3)".
boolean	allowExtend()	Whether to allow mixing table columns with extended columns in INSERT (or UPSERT).
boolean	allowExtendedTrim()	Whether TRIM should support more than one trim character.
boolean	allowGeometry()	Whether to allow geo-spatial extensions, including the GEOMETRY type.
boolean	allowHyphenInUnquotedTableName()	Whether to allow hyphens in an unquoted table name.
boolean	allowLenientCoercion()	Whether to allow lenient type coercions.
boolean	allowNiladicConstantWithoutParentheses()	Whether to allow parentheses to be specified in calls to niladic functions of returned the specific constant value.
boolean	allowNiladicParentheses()	Whether to allow parentheses to be specified in calls to niladic functions and procedures (that is, functions and procedures with no parameters).
boolean	allowPluralTimeUnits()	Whether interval literals should allow plural time units such as "YEARS" and "DAYS" in interval literals.
boolean	allowQualifyingCommonColumn()	Whether to allow a qualified common column in a query that has a NATURAL join or a join with a USING clause.
boolean	checkedArithmetic()	Whether the implementation uses checked arithmetic.
boolean	isApplyAllowed()	Whether CROSS APPLY and OUTER APPLY operators are allowed in the parser.
boolean	isBangEqualAllowed()	Whether the bang-equal token != is allowed as an alternative to <> in the parser.
boolean	isFromRequired()	Whether FROM clause is required in a SELECT statement.
boolean	isGroupByAlias()	Whether to allow aliases from the SELECT clause to be used as column names in the GROUP BY clause.
boolean	isGroupByOrdinal()	Whether GROUP BY 2 is interpreted to mean 'group by the 2nd column in the select list'.
boolean	isHavingAlias()	Whether to allow aliases from the SELECT clause to be used as column names in the HAVING clause.
boolean	isInsertSubsetColumnsAllowed()	Whether to allow INSERT (or UPSERT) with no column list but fewer values than the target table.
boolean	isLiberal()	Whether this dialect supports features from a wide variety of dialects.
boolean	isLimitStartCountAllowed()	Whether to allow the SQL syntax "LIMIT start, count".
boolean	isMinusAllowed()	Whether MINUS is allowed as an alternative to EXCEPT in the parser.
boolean	isNonStrictGroupBy()	Allow non-GROUP BY columns in SELECT (MySQL loose mode).
boolean	isOffsetLimitAllowed()	Whether to allow the SQL syntax "OFFSET start LIMIT count" (that is, OFFSET before LIMIT, in addition to LIMIT before OFFSET and OFFSET before FETCH).
boolean	isPercentRemainderAllowed()	Whether the "%" operator is allowed by the parser as an alternative to the mod function.
SqlConformance.SelectAliasLookup	isSelectAlias()	Whether to allow aliases from the SELECT clause to be used as column names in the same SELECT clause.
boolean	isSortByAlias()	Whether 'ORDER BY x' is interpreted to mean 'sort by the select list item whose alias is x' even if there is a column called x.
boolean	isSortByAliasObscures()	Whether "empno" is invalid in "select empno as x from emp order by empno" because the alias "x" obscures it.
boolean	isSortByOrdinal()	Whether 'ORDER BY 2' is interpreted to mean 'sort by the 2nd column in the select list'.
boolean	isSupportedDualTable()	Whether this dialect supports dual table.
boolean	isValueAllowed()	Whether VALUE is allowed as an alternative to VALUES in the parser.
SqlLibrary	semantics()	Controls the behavior of operators that are part of Standard SQL but nevertheless have different behavior in different databases.
boolean	shouldConvertRaggedUnionTypesToVarying()	Whether the least restrictive type of a number of CHAR types of different lengths should be a VARCHAR type.
boolean	splitQuotedTableName()	Whether to split a quoted table name.
boolean	supportsUnsignedTypes()	True when the unsigned versions of integer types are supported.

Field Details

DEFAULT

@Deprecated
static final SqlConformanceEnum DEFAULT

Deprecated.

Short-cut for SqlConformanceEnum.DEFAULT.

STRICT_92

@Deprecated
static final SqlConformanceEnum STRICT_92

Deprecated.

Short-cut for SqlConformanceEnum.STRICT_92.

STRICT_99

@Deprecated
static final SqlConformanceEnum STRICT_99

Deprecated.

Short-cut for SqlConformanceEnum.STRICT_99.

PRAGMATIC_99

@Deprecated
static final SqlConformanceEnum PRAGMATIC_99

Deprecated.

Short-cut for SqlConformanceEnum.PRAGMATIC_99.

ORACLE_10

@Deprecated
static final SqlConformanceEnum ORACLE_10

Deprecated.

Short-cut for SqlConformanceEnum.ORACLE_10.

STRICT_2003

@Deprecated
static final SqlConformanceEnum STRICT_2003

Deprecated.

Short-cut for SqlConformanceEnum.STRICT_2003.

PRAGMATIC_2003

@Deprecated
static final SqlConformanceEnum PRAGMATIC_2003

Deprecated.

Short-cut for SqlConformanceEnum.PRAGMATIC_2003.

Method Details

isLiberal

boolean isLiberal()

Whether this dialect supports features from a wide variety of dialects. This is enabled for the Babel parser, disabled otherwise.

allowCharLiteralAlias

boolean allowCharLiteralAlias()

Whether this dialect allows character literals as column aliases.

For example,

   SELECT empno, sal + comm AS 'remuneration'
   FROM Emp

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.BIG_QUERY, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.SQL_SERVER_2008; false otherwise.

isGroupByAlias

boolean isGroupByAlias()

Whether to allow aliases from the SELECT clause to be used as column names in the GROUP BY clause.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.BIG_QUERY, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5; false otherwise.

isSelectAlias

SqlConformance.SelectAliasLookup isSelectAlias()

Whether to allow aliases from the SELECT clause to be used as column names in the same SELECT clause. E.g., SELECT 1 as X, X+1 as Y; Name lookup considers an identifier in the same SELECT only if other lookups failed. Supported by Spark, Snowflake, Redshift, DuckDB.

Note: this usually requires isGroupByAlias() to also return true.

isNonStrictGroupBy

boolean isNonStrictGroupBy()

Allow non-GROUP BY columns in SELECT (MySQL loose mode).

isGroupByOrdinal

boolean isGroupByOrdinal()

Whether GROUP BY 2 is interpreted to mean 'group by the 2nd column in the select list'.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.BIG_QUERY, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.PRESTO; false otherwise.

isHavingAlias

boolean isHavingAlias()

Whether to allow aliases from the SELECT clause to be used as column names in the HAVING clause.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.BIG_QUERY, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5; false otherwise.

isSortByOrdinal

boolean isSortByOrdinal()

Whether 'ORDER BY 2' is interpreted to mean 'sort by the 2nd column in the select list'.

Among the built-in conformance levels, true in SqlConformanceEnum.DEFAULT, SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.PRAGMATIC_99, SqlConformanceEnum.PRAGMATIC_2003, SqlConformanceEnum.PRESTO, SqlConformanceEnum.SQL_SERVER_2008, SqlConformanceEnum.STRICT_92; false otherwise.

isSortByAlias

boolean isSortByAlias()

Whether 'ORDER BY x' is interpreted to mean 'sort by the select list item whose alias is x' even if there is a column called x.

Among the built-in conformance levels, true in SqlConformanceEnum.DEFAULT, SqlConformanceEnum.BABEL, SqlConformanceEnum.BIG_QUERY, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.SQL_SERVER_2008, SqlConformanceEnum.STRICT_92; false otherwise.

isSortByAliasObscures

boolean isSortByAliasObscures()

Whether "empno" is invalid in "select empno as x from emp order by empno" because the alias "x" obscures it.

Among the built-in conformance levels, true in SqlConformanceEnum.STRICT_92; false otherwise.

isSupportedDualTable

boolean isSupportedDualTable()

Whether this dialect supports dual table.

For example,

SELECT 1 + 1 FROM DUAL

Among the built-in conformance levels, true in SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, false otherwise.

isFromRequired

boolean isFromRequired()

Whether FROM clause is required in a SELECT statement.

Among the built-in conformance levels, true in SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.STRICT_92, SqlConformanceEnum.STRICT_99, SqlConformanceEnum.STRICT_2003; false otherwise.

splitQuotedTableName

boolean splitQuotedTableName()

Whether to split a quoted table name. If true, `x.y.z` is parsed as if the user had written `x`.`y`.`z`.

Among the built-in conformance levels, true in SqlConformanceEnum.BIG_QUERY; false otherwise.

allowHyphenInUnquotedTableName

boolean allowHyphenInUnquotedTableName()

Whether to allow hyphens in an unquoted table name.

If true, SELECT * FROM foo-bar.baz-buzz is valid, and is parsed as if the user had written SELECT * FROM `foo-bar`.`baz-buzz`.

Among the built-in conformance levels, true in SqlConformanceEnum.BIG_QUERY; false otherwise.

isBangEqualAllowed

boolean isBangEqualAllowed()

Whether the bang-equal token != is allowed as an alternative to <> in the parser.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.PRESTO; false otherwise.

isPercentRemainderAllowed

boolean isPercentRemainderAllowed()

Whether the "%" operator is allowed by the parser as an alternative to the mod function.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.PRESTO; false otherwise.

isMinusAllowed

boolean isMinusAllowed()

Whether MINUS is allowed as an alternative to EXCEPT in the parser.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12; false otherwise.

Note: MySQL does not support MINUS or EXCEPT (as of version 5.5).

isApplyAllowed

boolean isApplyAllowed()

Whether CROSS APPLY and OUTER APPLY operators are allowed in the parser.

APPLY invokes a table-valued function for each row returned by a table expression. It is syntactic sugar:

• SELECT * FROM emp CROSS APPLY TABLE(promote(empno)
  is equivalent to
  SELECT * FROM emp CROSS JOIN LATERAL TABLE(promote(empno)
• SELECT * FROM emp OUTER APPLY TABLE(promote(empno)
  is equivalent to
  SELECT * FROM emp LEFT JOIN LATERAL TABLE(promote(empno) ON true

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.SQL_SERVER_2008; false otherwise.

isInsertSubsetColumnsAllowed

boolean isInsertSubsetColumnsAllowed()

Whether to allow INSERT (or UPSERT) with no column list but fewer values than the target table.

The N values provided are assumed to match the first N columns of the table, and for each of the remaining columns, the default value of the column is used. It is an error if any of these columns has no default value.

The default value of a column is specified by the DEFAULT clause in the CREATE TABLE statement, or is NULL if the column is not declared NOT NULL.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.PRAGMATIC_99, SqlConformanceEnum.PRAGMATIC_2003; false otherwise.

allowAliasUnnestItems

boolean allowAliasUnnestItems()

Whether directly alias array items in UNNEST.

E.g. in UNNEST(a_array, b_array) AS T(a, b), a and b will be aliases of elements in a_array and b_array respectively.

Without this flag set, T will be the alias of the element in a_array and a, b will be the top level fields of T if T is a STRUCT type.

Among the built-in conformance levels, true in SqlConformanceEnum.PRESTO; false otherwise.

allowNiladicParentheses

boolean allowNiladicParentheses()

Whether to allow parentheses to be specified in calls to niladic functions and procedures (that is, functions and procedures with no parameters).

For example, CURRENT_DATE is a niladic system function. In standard SQL it must be invoked without parentheses:

VALUES CURRENT_DATE

If allowNiladicParentheses, the following syntax is also valid:

VALUES CURRENT_DATE()

Of the popular databases, MySQL, Apache Phoenix and VoltDB allow this behavior; Apache Hive, HSQLDB, IBM DB2, Microsoft SQL Server, Oracle, PostgreSQL do not.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5; false otherwise.

allowNiladicConstantWithoutParentheses

boolean allowNiladicConstantWithoutParentheses()

Whether to allow parentheses to be specified in calls to niladic functions of returned the specific constant value.

For example, PI is a niladic function and return specific constant values pi. In standard SQL it must be invoked with parentheses:

VALUES PI()

If allowNiladicConstantWithoutParentheses, the following syntax is also valid:

VALUES PI

The same function include E which result is Euler's constant.

Among the built-in conformance levels, true in SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.DEFAULT; SqlConformanceEnum.LENIENT; false otherwise.

allowExplicitRowValueConstructor

boolean allowExplicitRowValueConstructor()

Whether to allow SQL syntax "ROW(expr1, expr2, expr3)".

The equivalent syntax in standard SQL is "(expr1, expr2, expr3)".

Standard SQL does not allow this because the type is not well-defined. However, PostgreSQL allows this behavior.

Standard SQL allows row expressions in other contexts, for instance inside VALUES clause.

Among the built-in conformance levels, true in SqlConformanceEnum.DEFAULT, SqlConformanceEnum.LENIENT, SqlConformanceEnum.PRESTO; false otherwise.

allowExtend

boolean allowExtend()

Whether to allow mixing table columns with extended columns in INSERT (or UPSERT).

For example, suppose that the declaration of table T has columns A and B, and you want to insert data of column C INTEGER not present in the table declaration as an extended column. You can specify the columns in an INSERT statement as follows:

INSERT INTO T (A, B, C INTEGER) VALUES (1, 2, 3)

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT; false otherwise.

isLimitStartCountAllowed

boolean isLimitStartCountAllowed()

Whether to allow the SQL syntax "LIMIT start, count".

The equivalent syntax in standard SQL is "OFFSET start ROW FETCH FIRST count ROWS ONLY", and in PostgreSQL "LIMIT count OFFSET start".

MySQL and CUBRID allow this behavior.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5; false otherwise.

isOffsetLimitAllowed

boolean isOffsetLimitAllowed()

Whether to allow the SQL syntax "OFFSET start LIMIT count" (that is, OFFSET before LIMIT, in addition to LIMIT before OFFSET and OFFSET before FETCH).

The equivalent syntax in standard SQL is "OFFSET start ROW FETCH FIRST count ROWS ONLY".

Trino allows this behavior.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT; false otherwise.

allowGeometry

boolean allowGeometry()

Whether to allow geo-spatial extensions, including the GEOMETRY type.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.PRESTO, SqlConformanceEnum.SQL_SERVER_2008; false otherwise.

shouldConvertRaggedUnionTypesToVarying

boolean shouldConvertRaggedUnionTypesToVarying()

Whether the least restrictive type of a number of CHAR types of different lengths should be a VARCHAR type. And similarly BINARY to VARBINARY.

For example, consider the query

SELECT 'abcde' UNION SELECT 'xyz'

The input columns have types CHAR(5) and CHAR(3), and we need a result type that is large enough for both:

• Under strict SQL:2003 behavior, its column has type CHAR(5), and the value in the second row will have trailing spaces.
• With lenient behavior, its column has type VARCHAR(5), and the values have no trailing spaces.

Among the built-in conformance levels, true in SqlConformanceEnum.PRAGMATIC_99, SqlConformanceEnum.PRAGMATIC_2003, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.PRESTO, SqlConformanceEnum.SQL_SERVER_2008; SqlConformanceEnum.BIG_QUERY false otherwise.

allowExtendedTrim

boolean allowExtendedTrim()

Whether TRIM should support more than one trim character.

For example, consider the query

SELECT TRIM('eh' FROM 'hehe__hehe')

Under strict behavior, if the length of trim character is not 1, TRIM throws an exception, and the query fails. However many implementations (in databases such as MySQL and SQL Server) trim all the characters, resulting in a return value of '__'.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5, SqlConformanceEnum.SQL_SERVER_2008; false otherwise.

allowPluralTimeUnits

boolean allowPluralTimeUnits()

Whether interval literals should allow plural time units such as "YEARS" and "DAYS" in interval literals.

Under strict behavior, INTERVAL '2' DAY is valid and INTERVAL '2' DAYS is invalid; PostgreSQL allows both; Oracle only allows singular time units.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT; false otherwise.

allowQualifyingCommonColumn

boolean allowQualifyingCommonColumn()

Whether to allow a qualified common column in a query that has a NATURAL join or a join with a USING clause.

For example, in the query

SELECT emp.deptno
 FROM emp
 JOIN dept USING (deptno)

deptno is the common column. A qualified common column such as emp.deptno is not allowed in Oracle, but is allowed in PostgreSQL.

Among the built-in conformance levels, false in SqlConformanceEnum.ORACLE_10, SqlConformanceEnum.ORACLE_12, SqlConformanceEnum.PRESTO, SqlConformanceEnum.STRICT_92, SqlConformanceEnum.STRICT_99, SqlConformanceEnum.STRICT_2003; true otherwise.

isValueAllowed

boolean isValueAllowed()

Whether VALUE is allowed as an alternative to VALUES in the parser.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, SqlConformanceEnum.LENIENT, SqlConformanceEnum.MYSQL_5; false otherwise.

semantics

SqlLibrary semantics()

Controls the behavior of operators that are part of Standard SQL but nevertheless have different behavior in different databases.

Consider the SUBSTRING operator. In ISO standard SQL, negative start indexes are converted to 1; in Google BigQuery, negative start indexes are treated as offsets from the end of the string. For example, SUBSTRING('abcde' FROM -3 FOR 2) returns 'ab' in standard SQL and 'cd' in BigQuery.

If you specify conformance=BIG_QUERY in your connection parameters, SUBSTRING will give the BigQuery behavior. Similarly MySQL and Oracle.

Among the built-in conformance levels:

• SqlConformanceEnum.BIG_QUERY returns SqlLibrary.BIG_QUERY;
• SqlConformanceEnum.MYSQL_5 returns SqlLibrary.MYSQL;
• SqlConformanceEnum.ORACLE_10 and SqlConformanceEnum.ORACLE_12 return SqlLibrary.ORACLE;
• otherwise returns SqlLibrary.STANDARD.

allowLenientCoercion

boolean allowLenientCoercion()

Whether to allow lenient type coercions.

Coercions include:

• Coercion of string literal to array literal. For example, SELECT ARRAY[0,1,2] == '{0,1,2}'
• Casting BOOLEAN values to one of the following numeric types: TINYINT, SMALLINT, INTEGER, BIGINT.

Among the built-in conformance levels, true in SqlConformanceEnum.BABEL, false otherwise.

checkedArithmetic

boolean checkedArithmetic()

Whether the implementation uses checked arithmetic. Most SQL dialects use checked arithmetic at runtime: they terminate with a fatal error on overflow.

supportsUnsignedTypes

boolean supportsUnsignedTypes()

True when the unsigned versions of integer types are supported.