Array

This section describes the differences between Oracle Database and GaussDB when the JDBC driver of the java.sql.Array type is used.

**Table 1** Constructor reference
Constructor	Oracle Database	GaussDB	API Difference
1. Use the static constructor of ArrayDescriptor to construct an ArrayDescriptor object. 2. Use ArrayDescriptor to construct an array object.	String typeName = "XXX"; Connection conn = getConnection(); Object[] elements = null; ArrayDescriptor desc = ArrayDescriptor.createDescriptor(typeName, conn); Array array = new ARRAY(desc, conn, elements);	String typeName = "xxx"; Connection conn = getConnection(); Object[] elements = null; ArrayDescriptor desc = ArrayDescriptor.getDescriptor(typeName, conn); Array array = new GaussArray(desc, elements);	Different names of the static constructor for ArrayDescriptor: In Oracle Database, it is createDescriptor, while in GaussDB it is getDescriptor. Different constructor names for arrays: In Oracle Database, it is ARRAY(ArrayDescriptor, Connection, Object), while in GaussDB, it is GaussArray(ArrayDescriptor, Object). Variable description: typeName indicates the type name and is case-sensitive. Generally, it uses uppercase in Oracle Database, while in GaussDB it is lowercase. conn indicates the connection object for the corresponding database. elements indicates the element data of the corresponding type.

GaussDB currently does not support the constructors not listed in the aforementioned table.
If the element type is a character type and the length of the construction input string exceeds that defined by the element type, Oracle Database reports an error during input parameter binding.
If the array type is the varray type and the number of elements exceeds the maximum length of varray, Oracle Database reports an error during input parameter binding.

GaussDB does not verify type modifiers when constructing or binding input parameters. When a database receives array objects and executes SQL statements, it decides whether to report an error.

**Table 2** API reference
Method	Return Value Type	Throws	GaussDB
getBaseTypeName()	String	SQLException	Supported.
getBaseType()	int	SQLException	Supported.
getArray()	Object	SQLException	Supported.
getArray(java.util.Map<String,Class<?>> map)	Object	SQLException	Not supported.
getArray(long index, int count)	Object	SQLException	Supported.
getArray(long index, int count, java.util.Map<String,Class<?>> map)	Object	SQLException	Not supported.
getResultSet()	ResultSet	SQLException	Not supported.
getResultSet(java.util.Map<String,Class<?>> map)	ResultSet	SQLException	Not supported.
getResultSet(long index, int count)	ResultSet	SQLException	Not supported.
getResultSet (long index, int count, java.util.Map<String,Class<?>> map)	ResultSet	SQLException	Not supported.
free()	void	SQLException	Not supported.

**Table 3** Differences in the getArray() API
Element Database Type	Actual Return Value Type of the getArray API (Oracle Database)	Actual Return Value Type of the getArray API (GaussDB)
CHAR	java.lang.String[]	java.lang.String[]
VARCHAR/VARCHAR2	java.lang.String[]	java.lang.String[]
NCHAR	java.lang.String[]	java.lang.String[]
NVARCHAR2	java.lang.String[]	java.lang.String[]
NUMBER	java.math.BigDecimal[]	java.math.BigDecimal[]
NUMERIC	java.math.BigDecimal[]	java.math.BigDecimal[]
DECIMAL	java.math.BigDecimal[]	java.math.BigDecimal[]
INTEGER	java.math.BigDecimal[]	java.lang.Integer[]
SMALLINT	java.math.BigDecimal[]	java.lang.Short[]
DOUBLE PRECISION	java.math.BigDecimal[]	java.lang.Double[]
FLOAT	java.math.BigDecimal[]	java.lang.Double[]
REAL	java.math.BigDecimal[]	java.lang.Float[]
BINARY_DOUBLE	java.lang.Double[]	java.lang.Double[]
BINARY_INTEGER	java.math.BigDecimal[]	java.lang.Integer[]
BOOLEAN	java.math.BigDecimal[]	java.lang.Boolean[]
TIMESTAMP	java.sql.Timestamp[]	java.sql.Timestamp[]
TIMESTAMP WITH TIME ZONE	java.time.OffsetDateTime[]	java.sql.Timestamp[]
BLOB	oracle.sql.BLOB[]	java.sql.Blob[]
CLOB	oracle.sql.CLOB[]	java.sql.Clob[]
Set/Array	java.lang.Object[]	java.sql.Array[]
RECORD	java.lang.Object[]	java.sql.Struct[]

GaussDB currently does not support the types unlisted in the aforementioned table.
For details about the differences in the return values of the getArray(long index, int count) API, see the preceding table.
The differences in index parameter of getArray(long index, int count) are as follows:
- The value range supported by Oracle Database is [1, Long.MAX_VALUE]. GaussDB supports a range of [1, Integer.MAX_VALUE].
- If the index value is greater than that of Integer.MAX_VALUE, it will be truncated in Oracle Database, while an error is reported in GaussDB.

**Table 4** Differences in the getBaseType() API
Element Database Type	Return Value of the getBaseType API (Oracle Database)	Return Value of the getBaseType API (GaussDB)
CHAR	java.sql.Types.CHAR	java.sql.Types.CHAR
VARCHAR/VARCHAR2	java.sql.Types.VARCHAR	java.sql.Types.VARCHAR
NCHAR	java.sql.Types.NCHAR	java.sql.Types.CHAR
NVARCHAR2	java.sql.Types.NVARCHAR	java.sql.Types.VARCHAR
NUMBER	java.sql.Types.NUMERIC	java.sql.Types.NUMERIC
NUMERIC	java.sql.Types.DECIMAL	java.sql.Types.NUMERIC
DECIMAL	java.sql.Types.DECIMAL	java.sql.Types.NUMERIC
INTEGER	java.sql.Types.NUMERIC	java.sql.Types.INTEGER
SMALLINT	java.sql.Types.NUMERIC	java.sql.Types.SMALLINT
DOUBLE PRECISION	java.sql.Types.FLOAT	java.sql.Types.DOUBLE
FLOAT	java.sql.Types.FLOAT	java.sql.Types.DOUBLE
REAL	java.sql.Types.FLOAT	java.sql.Types.REAL
BINARY_DOUBLE	oracle.jdbc.OracleTypes.BINARY_DOUBLE	java.sql.Types.DOUBLE
BINARY_INTEGER	java.sql.Types.NUMERIC	java.sql.Types.INTEGER
BOOLEAN	java.sql.Types.NUMERIC	java.sql.Types.BIT
TIMESTAMP	java.sql.Types.TIMESTAMP	java.sql.Types.TIMESTAMP
TIMESTAMP WITH TIME ZONE	oracle.jdbc.OracleTypes.TIMESTAMPTZ	java.sql.Types.TIMESTAMP
BLOB	java.sql.Types.BLOB	java.sql.Types.BLOB
CLOB	java.sql.Types.CLOB	java.sql.Types.CLOB
Set/Array	java.sql.Types.ARRAY	java.sql.Types.ARRAY
RECORD	java.sql.Types.STRUCT	java.sql.Types.STRUCT

GaussDB currently does not support the types unlisted in the aforementioned table.

**Table 5** Differences in the getBaseTypeName() API
Element Database Type	Return Value of the getBaseTypeName API (Oracle Database)	Return Value of the getBaseTypeName API (GaussDB)
CHAR	"CHAR"	"bpchar"
VARCHAR/VARCHAR2	"VARCHAR"	"varchar"
NCHAR	"NCHAR"	"bpchar"
NVARCHAR2	"NVARCHAR"	"nvarchar2"
NUMBER	"NUMBER"	"numeric"
NUMERIC	"DECIMAL"	"numeric"
DECIMAL	"DECIMAL"	"numeric"
INTEGER	"NUMBER"	"int4"
SMALLINT	"NUMBER"	"int2"
DOUBLE PRECISION	"FLOAT"	"float8"
FLOAT	"FLOAT"	"float8"
REAL	"FLOAT"	"float4"
BINARY_DOUBLE	"BINARY_DOUBLE"	"float8"
BINARY_INTEGER	"NUMBER"	"int4"
BOOLEAN	"NUMBER"	"bool"
TIMESTAMP	"TIMESTAMP"	"timestamp"
TIMESTAMP WITH TIME ZONE	"TIMESTAMP WITH TIME ZONE"	"timestamptz"
BLOB	"BLOB"	"blob"
CLOB	"CLOB"	"clob"
Set/Array	See the description below.	See the description below.
RECORD	See the description below.	See the description below.

GaussDB currently does not support the types unlisted in the aforementioned table.
When an element is of the set, array, or RECORD type that is defined within a package, the return rules for getBaseTypeName are as follows:
- OJDBC11 returns schemaName.packageName.typeName.
- OJDBC8 generally returns schemaName.packageName.typeName, or returns "schemaName"."packageName.typeName" in the following condition:
  Any of schemaName, packageName, or typeName does not meet the rule of starting with a letter followed by characters including letters, digits, or underscores.
- GaussDB generally returns schemaName.packageName.typeName, or returns "schemaName"."packageName"."typeName" in the following condition:
  Any of schemaName, packageName, or typeName does not meet the rule of starting with a letter or underscore followed by characters including letters, digits, or underscores.
When an element is of the set, array, or RECORD type that is defined in the schema (but not in the package), the return rules for getBaseTypeName are as follows:
- OJDBC11 returns schemaName.typeName.
- OJDBC8 generally returns schemaName.typeName, or returns "schemaName"."typeName" in the following condition:
  Any of schemaName or typeName does not meet the rule of starting with a letter followed by characters including letters, digits, or underscores.
- GaussDB generally returns schemaName.typeName, or returns "schemaName"."typeName" in the following condition:
  Any of schemaName or typeName does not meet the rule of starting with a letter or underscore followed by characters including letters, digits, or underscores.
If no special processing is performed during element type creation, the getBaseTypeName API typically returns the type name in uppercase in Oracle Database, while returns the type name in lowercase in GaussDB.

**Table 6** Differences in array construction APIs
Element Database Type	List of Java Types Supported by Element Input Parameters (Oracle Database OJDBC8)	List of Java Types Supported by Element Input Parameters (GaussDB)	Difference
CHAR	Any Java type	Byte, Short, Integer, Long, BigInteger, BigDecimal, Float, Double, Character, Boolean, java.sql.Date, java.sql.Time, java.sql.Timestamp, and PGClob	The different types supported by element input parameters can be seen in the table.
VARCHAR/VARCHAR2	Any Java type	Byte, Short, Integer, Long, BigInteger, BigDecimal, Float, Double, Character, Boolean, java.sql.Date, java.sql.Time, java.sql.Timestamp, and PGClob	The different types supported by element input parameters can be seen in the table.
NCHAR	Any Java type	Byte, Short, Integer, Long, BigInteger, BigDecimal, Float, Double, Character, Boolean, java.sql.Date, java.sql.Time, java.sql.Timestamp, and PGClob	The different types supported by element input parameters can be seen in the table.
NVARCHAR2	Any Java type	Byte, Short, Integer, Long, BigInteger, BigDecimal, Float, Double, Character, Boolean, java.sql.Date, java.sql.Time, java.sql.Timestamp, and PGClob	The different types supported by element input parameters can be seen in the table.
NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. When the input parameter is of the Float, Double, BigDecimal, or String type and the decimal part is 0, Oracle Database truncates the decimal part, while GaussDB retains it.
NUMERIC	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. When the input parameter is of the Float, Double, BigDecimal, or String type and the decimal part is 0, Oracle Database truncates the decimal part, while GaussDB retains it.
DECIMAL	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. When the input parameter is of the Float, Double, BigDecimal, or String type and the decimal part is 0, Oracle Database truncates the decimal part, while GaussDB retains it.
INTEGER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API. When the input parameter value exceeds the integer range, GaussDB reports an error.
SMALLINT	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API. When the input parameter exceeds the Short range, GaussDB reports an error.
DOUBLE PRECISION	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API. Converting a higher-precision type to Double may result in precision loss.
FLOAT	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API. Converting a higher-precision type to Double may result in precision loss.
REAL	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API. Converting a higher-precision type to Float may result in precision loss.
BINARY_DOUBLE	Double and oracle.sql.BINARY_DOUBLE	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API. Converting a higher-precision type to Double may result in precision loss.
BINARY_INTEGER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, AtomicInteger, AutomicLong, DoubleAccumulator, DoubleAddr, LongAccumulator, LondAdder, Striped64, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The input parameters of the OJDBC11 element support the following types: Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER. The target types are inconsistent. For details, see differences in the getArray() API. When the input value exceeds the Integer range, GaussDB reports an error. Oracle Database OJDBC8 performs data truncation.
BOOLEAN	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, AtomicInteger, AutomicLong, DoubleAccumulator, DoubleAddr, LongAccumulator, LondAdder, Striped64, String, and oracle.sql.NUMBER	Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, and String	The different types supported by element input parameters can be seen in the table. The input parameters of the OJDBC8 element support the following types: Byte, Short, Integer, Long, Float, Double, Boolean, BigDecimal, BigInteger, String, and oracle.sql.NUMBER. The target types are inconsistent. For details, see differences in the getArray() API. In GaussDB, the target data type is Boolean, which only supports inputs of 1, 0, "true", and "false".
TIMESTAMP	byte[], java.sql.Date, Calendar, java.util.Date, LocalDate, LocalDateTime, LocalTime, OffsetDateTime, OffsetTime, String, java.sql.Time, java.sql.Timestamp, oracle.sql.DATE, oracle.sql.TIMESTAMP, oracle.sql.TIMESTAMPTZ, oracle.sql.TIMESTAMPLTZ, and ZonedDateTime	java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp, LocalDateTime, and String	The different types supported by element input parameters can be seen in the table.
TIMESTAMP WITH TIME ZONE	java.sql.Date, Calendar, java.util.Date, LocalDate, LocalDateTime, LocalTime, OffsetDateTime, OffsetTime, String, java.sql.Time, java.sql.Timestamp, oracle.sql.DATE, oracle.sql.TIMESTAMP, oracle.sql.TIMESTAMPTZ, oracle.sql.TIMESTAMPLTZ, and ZonedDateTime	java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp, LocalDateTime, and String	The different types supported by element input parameters can be seen in the table. The target types are inconsistent. For details, see differences in the getArray() API.
BLOB	oracle.sql.BLOB and oracle.jdbc.driver.OracleBlob	PGBlob	The different types supported by element input parameters can be seen in the table.
CLOB	oracle.sql.CLOB, oracle.jdbc.driver.OracleClob, InputStream, and Reader	PGClob	The different types supported by element input parameters can be seen in the table.
Set/Array	Array and Object	GaussArray and Object	The different types supported by element input parameters can be seen in the table. Oracle Database: No error is reported when the input parameter is of the Array type even if the Array type differs from the element type. GaussDB: An error is reported when the input parameter is of the GaussArray type that differs from the element type. When the input parameter of an element is of the Object type, refer to the differences in array construction APIs.
RECORD	Struct and Object[]	GaussStruct and Object[]	The different types supported by element input parameters can be seen in the table. Oracle Database: No error is reported when the input parameter is of the Struct type even if the Struct type differs from the element type. GaussDB: An error is reported when the input parameter is of the GaussStruct type that differs from the element type. When the input parameter of an element is of the Object[] type, refer to the differences in struct construction APIs.

When an array is constructed, if the Java type of the input element does not match the target type, an implicit conversion operation is performed. For details on the Java types of input elements supported by various database element types, refer to the preceding table.
GaussDB currently does not support the types unlisted in the aforementioned table.
The constructor needs to provide an element array. The preceding table describes the differences between elements in the array.

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