CPLODBCStatement Class Reference

#include <cpl_odbc.h>

List of all members.

Public Member Functions
void	Clear ()
void	AppendEscaped (const char *)
void	Append (const char *)
void	Append (int)
void	Append (double)
int	Appendf (const char *,...)
int	ExecuteSQL (const char *=0)
int	Fetch (int nOrientation=SQL_FETCH_NEXT, int nOffset=0)
int	GetColCount ()
const char *	GetColName (int)
short	GetColType (int)
const char *	GetColTypeName (int)
short	GetColSize (int)
short	GetColPrecision (int)
short	GetColNullable (int)
int	GetColId (const char *)
const char *	GetColData (int, const char *=0)
const char *	GetColData (const char *, const char *=0)
int	GetColumns (const char *pszTable, const char *pszCatalog=0, const char *pszSchema=0)
int	GetPrimaryKeys (const char *pszTable, const char *pszCatalog=0, const char *pszSchema=0)
int	GetTables (const char *pszCatalog=0, const char *pszSchema=0)
void	DumpResult (FILE *fp, int bShowSchema=0)
Static Public Member Functions
static CPLString	GetTypeName (int)
static SQLSMALLINT	GetTypeMapping (SQLSMALLINT)

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Detailed Description

Abstraction for statement, and resultset.

Includes methods for executing an SQL statement, and for accessing the resultset from that statement. Also provides for executing other ODBC requests that produce results sets such as SQLColumns() and SQLTables() requests.

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Member Function Documentation

void CPLODBCStatement::Append

(

double

dfValue

)

Append to internal command.

The passed value is formatted and appended to the internal SQL command text.

Parameters:

dfValue

value to append to the command.

References Append().

void CPLODBCStatement::Append

(

int

nValue

)

Append to internal command.

The passed value is formatted and appended to the internal SQL command text.

Parameters:

nValue

value to append to the command.

References Append().

void CPLODBCStatement::Append

(

const char *

pszText

)

Append text to internal command.

The passed text is appended to the internal SQL command text.

Parameters:

pszText

text to append.

Referenced by Append(), AppendEscaped(), Appendf(), and ExecuteSQL().

void CPLODBCStatement::AppendEscaped

(

const char *

pszText

)

Append text to internal command.

The passed text is appended to the internal SQL command text after escaping any special characters so it can be used as a character string in an SQL statement.

Parameters:

pszText

text to append.

References Append().

int CPLODBCStatement::Appendf	(	const char *	pszFormat,
			...
	)

Append to internal command.

The passed format is used to format other arguments and the result is appended to the internal command text. Long results may not be formatted properly, and should be appended with the direct Append() methods.

Parameters:

pszFormat

printf() style format string.

Returns:

FALSE if formatting fails dueto result being too large.

References Append().

void CPLODBCStatement::Clear

(

)

Clear internal command text and result set definitions.

Referenced by ExecuteSQL().

void CPLODBCStatement::DumpResult	(	FILE *	fp,
		int	bShowSchema = 0
	)

Dump resultset to file.

The contents of the current resultset are dumped in a simply formatted form to the provided file. If requested, the schema definition will be written first.

Parameters:

	fp	the file to write to. stdout or stderr are acceptable.
	bShowSchema	TRUE to force writing schema information for the rowset before the rowset data itself. Default is FALSE.

References Fetch(), GetColCount(), GetColData(), GetColName(), GetColNullable(), GetColPrecision(), GetColSize(), GetColType(), and GetTypeName().

int CPLODBCStatement::ExecuteSQL

(

const char *

pszStatement = 0

)

Execute an SQL statement.

This method will execute the passed (or stored) SQL statement, and initialize information about the resultset if there is one. If a NULL statement is passed, the internal stored statement that has been previously set via Append() or Appendf() calls will be used.

Parameters:

pszStatement

the SQL statement to execute, or NULL if the internally saved one should be used.

Returns:

TRUE on success or FALSE if there is an error. Error details can be fetched with OGRODBCSession::GetLastError().

References Append(), and Clear().

int CPLODBCStatement::Fetch	(	int	nOrientation = SQL_FETCH_NEXT,
		int	nOffset = 0
	)

Fetch a new record.

Requests the next row in the current resultset using the SQLFetchScroll() call. Note that many ODBC drivers only support the default forward fetching one record at a time. Only SQL_FETCH_NEXT (the default) should be considered reliable on all drivers.

Currently it isn't clear how to determine whether an error or a normal out of data condition has occured if Fetch() fails.

Parameters:

	nOrientation	One of SQL_FETCH_NEXT, SQL_FETCH_LAST, SQL_FETCH_PRIOR, SQL_FETCH_ABSOLUTE, or SQL_FETCH_RELATIVE (default is SQL_FETCH_NEXT).
	nOffset	the offset (number of records), ignored for some orientations.

Returns:

TRUE if a new row is successfully fetched, or FALSE if not.

References CPLODBCSession::GetLastError(), and GetTypeMapping().

Referenced by DumpResult().

int CPLODBCStatement::GetColCount

(

)

Fetch the resultset column count.

Returns:

the column count, or zero if there is no resultset.

Referenced by DumpResult().

const char * CPLODBCStatement::GetColData	(	const char *	pszColName,
		const char *	pszDefault = 0
	)

Fetch column data.

Fetches the data contents of the requested column for the currently loaded row. The result is returned as a string regardless of the column type. NULL is returned if an illegal column is given, or if the actual column is "NULL".

Parameters:

	pszColName	the name of the column requested.
	pszDefault	the value to return if the column does not exist, or is NULL. Defaults to NULL.

Returns:

pointer to internal column data or NULL on failure.

References GetColData(), and GetColId().

const char * CPLODBCStatement::GetColData	(	int	iCol,
		const char *	pszDefault = 0
	)

Fetch column data.

Fetches the data contents of the requested column for the currently loaded row. The result is returned as a string regardless of the column type. NULL is returned if an illegal column is given, or if the actual column is "NULL".

Parameters:

	iCol	the zero based column to fetch.
	pszDefault	the value to return if the column does not exist, or is NULL. Defaults to NULL.

Returns:

pointer to internal column data or NULL on failure.

Referenced by DumpResult(), and GetColData().

int CPLODBCStatement::GetColId

(

const char *

pszColName

)

Fetch column index.

Gets the column index corresponding with the passed name. The name comparisons are case insensitive.

Parameters:

pszColName

the name to search for.

Returns:

the column index, or -1 if not found.

Referenced by GetColData().

const char * CPLODBCStatement::GetColName

(

int

iCol

)

Fetch a column name.

Parameters:

iCol

the zero based column index.

Returns:

NULL on failure (out of bounds column), or a pointer to an internal copy of the column name.

Referenced by DumpResult().

short CPLODBCStatement::GetColNullable

(

int

iCol

)

Fetch the column nullability.

Parameters:

iCol

the zero based column index.

Returns:

TRUE if the column may contains or FALSE otherwise.

Referenced by DumpResult().

short CPLODBCStatement::GetColPrecision

(

int

iCol

)

Fetch the column precision.

Parameters:

iCol

the zero based column index.

Returns:

column precision, may be zero or the same as column size for columns to which it does not apply.

Referenced by DumpResult().

short CPLODBCStatement::GetColSize

(

int

iCol

)

Fetch the column width.

Parameters:

iCol

the zero based column index.

Returns:

column width, zero for unknown width columns.

Referenced by DumpResult().

short CPLODBCStatement::GetColType

(

int

iCol

)

Fetch a column data type.

The return type code is a an ODBC SQL_ code, one of SQL_UNKNOWN_TYPE, SQL_CHAR, SQL_NUMERIC, SQL_DECIMAL, SQL_INTEGER, SQL_SMALLINT, SQL_FLOAT, SQL_REAL, SQL_DOUBLE, SQL_DATETIME, SQL_VARCHAR, SQL_TYPE_DATE, SQL_TYPE_TIME, SQL_TYPE_TIMESTAMPT.

Parameters:

iCol

the zero based column index.

Returns:

type code or -1 if the column is illegal.

Referenced by DumpResult().

const char * CPLODBCStatement::GetColTypeName

(

int

iCol

)

Fetch a column data type name.

Returns data source-dependent data type name; for example, "CHAR", "VARCHAR", "MONEY", "LONG VARBINAR", or "CHAR ( ) FOR BIT DATA".

Parameters:

iCol

the zero based column index.

Returns:

NULL on failure (out of bounds column), or a pointer to an internal copy of the column dat type name.

int CPLODBCStatement::GetColumns	(	const char *	pszTable,
		const char *	pszCatalog = 0,
		const char *	pszSchema = 0
	)

Fetch column definitions for a table.

The SQLColumn() method is used to fetch the definitions for the columns of a table (or other queriable object such as a view). The column definitions are digested and used to populate the CPLODBCStatement column definitions essentially as if a "SELECT * FROM tablename" had been done; however, no resultset will be available.

Parameters:

	pszTable	the name of the table to query information on. This should not be empty.
	pszCatalog	the catalog to find the table in, use NULL (the default) if no catalog is available.
	pszSchema	the schema to find the table in, use NULL (the default) if no schema is available.

Returns:

TRUE on success or FALSE on failure.

int CPLODBCStatement::GetPrimaryKeys	(	const char *	pszTable,
		const char *	pszCatalog = 0,
		const char *	pszSchema = 0
	)

Fetch primary keys for a table.

The SQLPrimaryKeys() function is used to fetch a list of fields forming the primary key. The result is returned as a result set matching the SQLPrimaryKeys() function result set. The 4th column in the result set is the column name of the key, and if the result set contains only one record then that single field will be the complete primary key.

Parameters:

	pszTable	the name of the table to query information on. This should not be empty.
	pszCatalog	the catalog to find the table in, use NULL (the default) if no catalog is available.
	pszSchema	the schema to find the table in, use NULL (the default) if no schema is available.

Returns:

TRUE on success or FALSE on failure.

int CPLODBCStatement::GetTables	(	const char *	pszCatalog = 0,
		const char *	pszSchema = 0
	)

Fetch tables in database.

The SQLTables() function is used to fetch a list tables in the database. The result is returned as a result set matching the SQLTables() function result set. The 3rd column in the result set is the table name. Only tables of type "TABLE" are returned.

Parameters:

	pszCatalog	the catalog to find the table in, use NULL (the default) if no catalog is available.
	pszSchema	the schema to find the table in, use NULL (the default) if no schema is available.

Returns:

TRUE on success or FALSE on failure.

SQLSMALLINT CPLODBCStatement::GetTypeMapping

(

SQLSMALLINT

nTypeCode

)

[static]

Get appropriate C data type for SQL column type.

Returns a C data type code, corresponding to the indicated SQL data type code (as returned from CPLODBCStatement::GetColType()).

Parameters:

nTypeCode

the SQL_ code, such as SQL_CHAR.

Returns:

data type code. The valid code is always returned. If SQL code is not recognised, SQL_C_BINARY will be returned.

Referenced by Fetch().

CPLString CPLODBCStatement::GetTypeName

(

int

nTypeCode

)

[static]

Get name for SQL column type.

Returns a string name for the indicated type code (as returned from CPLODBCStatement::GetColType()).

Parameters:

nTypeCode

the SQL_ code, such as SQL_CHAR.

Returns:

internal string, "UNKNOWN" if code not recognised.

Referenced by DumpResult().

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The documentation for this class was generated from the following files:

• cpl_odbc.h
• cpl_odbc.cpp