Index / Glossary
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
C   Column
 

A column is another name for field in a SQL table. It has a data type (Integer, Char, Money etc) and a name by which it is addressed.

You specify the name of a column in a query (either DELETE, UPDATE, SELECT or INSERT)
D   data source
  A data source defines all informationen needed by ODBC to connect to a database. This includes the name of the driver to use (Postgres, mySQL etc.), the name of the user, his password, the server name on which the database resides and of course the name of the database. There are a lot more options available.
  Data Types
 

The following table show some ODBC data types and how the relate to standard C data types:

Type identifier ODBC typedef C typedef
SQL_C_CHAR SQLCHAR * unsigned char *
SQL_C_SSHORT SQLSMALLINT short int
SQL_C_USHORT SQLUSMALLINT unsigned short int
SQL_C_SLONG SQLINTEGER long int
SQL_C_FLOAT SQLREAL float
SQL_C_DOUBLE SQLDOUBLE, SQLFLOAT double
SQL_C_BINARY SQLCHAR * unsigned char
SQL_C_TYPE_DATE SQL_DATE_STRUCT struct
tagDATE_STRUCT {
SQLSMALLINT year;
SQLUSMALLINT month;
SQLUSMALLINT day;
} DATE_STRUCT;
SQL_C_TYPE_TIME SQL_TIME_STRUCT struct
tagTIME_STRUCT {
SQLUSMALLINT hour;
SQLUSMALLINT minute;
SQLUSMALLINT second;
} TIME_STRUCT;

You will need the type identifier in calls to SQLBindCol.

 
O   odbc.ini
  /etc/odbc.ini is the configuration file for system data sources. It contains information which will be needed when connecting to a database. It is modified by a graphical utility ODBCConfig.
R   Row
  A row is a set of columns in a query. For example in our table there are two users. Each user makes up a row in the table or in the result of our query.
S   SQLAllocHandle
  allocates needed handles. 
SQLRETURN 
SQLAllocHandle(SQLSMALLINT  HandleType,     
               SQLHANDLE    InputHandle, 
               SQLHANDLE   *OutputHandlePtr);

Arguments

HandleType

Defines the type of handle to be allocated by SQLAllocHandle. There are four possible values:

SQL_HANDLE_ENV
SQL_HANDLE_DBC
SQL_HANDLE_STMT
SQL_HANDLE_DESC
InputHandle
This is the input handle in whose context the new handle will be allocated. If HandleType is SQL_HANDLE_ENV, this is SQL_NULL_HANDLE. For a handle of type SQL_HANDLE_DBC, this has to be an environment handle, and if it is SQL_HANDLE_STMT or SQL_HANDLE_DESC, it must be a connection handle.
OutputHandlePtr
Pointer to a buffer in which to return the allocated handle.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_INVALID_HANDLE, or SQL_ERROR.
  SQLBindCol
  binds a variable to a column in the result. 
SQLRETURN 
SQLBindCol(SQLHSTMT      StatementHandle, 
           SQLUSMALLINT  ColumnNumber, 
           SQLSMALLINT   TargetType,  
           SQLPOINTER    TargetValuePtr, 
           SQLINTEGER    BufferLength, 
           SQLINTEGER   *StrLen_or_IndPtr);

Arguments

StatementHandle
StatementHandle must have been allocated by SQLAllocHandle and will hold all information and the result set of the statement.
ColumnNumber
Number of the column in the result set. Starts with 1.
TargetType
Type identifier of the data type
TargetValuePtr
The pointer to the variable in which the data will be stored.
BufferLength
The size of the buffer TargetValuePtr points at in bytes.
StrLen_or_IndPtr
When data is fetched, returns either
  • The length of the data available to return
  • SQL_NO_TOTAL
  • SQL_NULL_DATA

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_ERROR or SQL_INVALID_HANDLE.
  SQLConnect
  connects to a datasource 
SQLRETURN SQLConnect(SQLHDBC     ConnectionHandle, 
                     SQLCHAR    *ServerName, 
                     SQLSMALLINT NameLength1, 
                     SQLCHAR    *UserName, 
                     SQLSMALLINT NameLength2, 
                     SQLCHAR    *Authentication, 
                     SQLSMALLINT NameLength3);

Arguments

ConnectionHandle
ConnectionHandle must have been allocated by SQLAllocHandle and will hold all information about the connection.
ServerName
Name of the database server
NameLength1
The length of ServerName or SQL_NTS
UserName
The name of the user who connects to the database.
NameLength2
The length of UserName or SQL_NTS
Authentication
Password of the user
NameLength3
The length of Authentication or SQL_NTS

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_ERROR or SQL_INVALID_HANDLE.
  SQLDataSources
  fetches avaible datasource names either user, system or both. 
SQLRETURN 
SQLDataSources(SQLHENV      EnvironmentHandle, 
               SQLUSMALLINT Direction, 
               SQLCHAR     *ServerName, 
               SQLSMALLINT  BufferLength1, 
               SQLSMALLINT *NameLength1Ptr, 
               SQLCHAR     *Description, 
               SQLSMALLINT  BufferLength2, 
               SQLSMALLINT *NameLength2Ptr);

Arguments

EnvironmentHandle
EnvironmentHandle must have been allocated by SQLAllocHandle.
Direction
Which DSN we are looking for. May be on of:
SQL_FETCH_FIRST Sets up SQLDataSources() to lookup the first of all available datasources (either user or systemwide).
SQL_FETCH_FIRST_USER Sets up SQLDataSources() to lookup the first of the available user datasources.
SQL_FETCH_FIRST_SYSTEM Sets up SQLDataSources() to lookup the first of the available system datasources.
SQL_FETCH_NEXT Fetches the next datasource. Depending on SQL_FETCH_FIRST_USER, SQL_FETCH_FIRST_SYSTEM or SQL_FETCH_FIRST this may only be a user datasource, only a system datasource or one of either.
ServerName
The name of the datasource is returned herein.
BufferLength1
Defines how many chars Servername may contain at most.
NameLength1Ptr
The pointer to the variable in which the actual length of the datasource name is stored. If NameLength1Ptr is greater than BufferLength1, then the DSN in ServerName is truncated to fit.
BufferLength
The size of the buffer TargetValuePtr points at in bytes.
Description
The description supplied with the datasource, giving more information on the datasource in human readable form.
BufferLength2
Defines how many chars Description may contain at most.
NameLength2Ptr
The pointer to the variable in which the actual length of the description is stored. If NameLength2Ptr is greater than BufferLength2, then the description in Description is truncated to fit.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_ERROR, SQL_NO_DATA> or SQL_INVALID_HANDLE.
  SQLExecDirect
  Executes a SQL statement 
SQLRETURN SQLExecDirect(SQLHSTMT    StatementHandle, 
                        SQLCHAR    *StatementText, 
                        SQLINTEGER  TextLength);

Arguments

StatementHandle
StatementHandle must have been allocated by SQLAllocHandle and will hold all information and the result set of the statement.
StatementText
The SQL statement to be executed
TextLength
The length of StatementText or SQL_NTS

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_ERROR or SQL_INVALID_HANDLE.
  SQLDisconnect
  disconnects the specified connection 
SQLRETURN SQLDisconnect(SQLHDBC     ConnectionHandle);

Arguments

ConnectionHandle
The handle of the connection to be closed.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_INVALID_HANDLE, or SQL_ERROR.
  SQLFetch
  Fetches the next row of the result set. 
SQLRETURN SQLFetch(SQLHDBC     StatementHandle);

Arguments

StatementHandle
The handle of the statement to be closed fromwhich the data should be fetched.

Returns

SQL_SUCCESS, SQL_NO_DATA, SQL_STILL_EXECUTING, SQL_SUCCESS_WITH_INFO, SQL_INVALID_HANDLE, or SQL_ERROR.
  SQLFreeHandle
  frees allocated handles. 
SQLRETURN SQLFreeHandle(SQLSMALLINT  HandleType,     
                        SQLHANDLE    InputHandle);

Arguments

HandleType

Defines the type of handle to be freed. There are four possible values:

SQL_HANDLE_ENV
SQL_HANDLE_DBC
SQL_HANDLE_STMT
SQL_HANDLE_DESC
InputHandle
The handle to be freed. Should match the type stated by HandleType

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_INVALID_HANDLE, or SQL_ERROR.
  SQLNumResultCols
  returns the number of columns in the result set. 
SQLRETURN SQLNumResultCols(SQLHSTMT     StatementHandle, 
                           SQLSMALLINT *ColumnCountPtr);

Arguments

StatementHandle
StatementHandle must have been allocated by SQLAllocHandle and holds all information and the result set of the statement.
ColumnCountPtr
A pointer to a variable to hold the result value.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_STILL_EXECUTING, SQL_INVALID_HANDLE, or SQL_ERROR.
  SQLRowCount
  returns the number of rows affected by INSERT, UPDATE or DELETE. Many drivers (but not all) return the number of rows returned by the last executed SELECT statement too. 
SQLRETURN SQLSQLRowCount(SQLHSTMT     StatementHandle, 
                         SQLSMALLINT *RowCountPtr);

Arguments

StatementHandle
StatementHandle must have been allocated by SQLAllocHandle and holds all information and the result set of the statement.
RowCountPtr
A pointer to a variable to hold the result value.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_STILL_EXECUTING, SQL_INVALID_HANDLE, or SQL_ERROR.
  SQLSetConnectAttr
  modifies attributes of connections. 
SQLRETURN SQLSetConnectAttr(SQLHDBC    ConnectionHandle, 
                            SQLINTEGER Attribute, 
                            SQLPOINTER ValuePtr, 
                            SQLINTEGER StringLength);

Arguments

ConnectionHandle
ConnectionHandle must have been allocated by SQLAllocHandle and defines the connection which will be modified.
Attribute
which attribute to set
ValuePtr
Pointer to the value for Attribute. Depending on Attribute, ValuePtr will be a 32-bit integer value or a pointer to a null-terminated string.
StringLength
If ValuePtr points to a character string or a binary buffer, this argument should be the length of *ValuePtr. Otherwise, for ValuePtr of type integer StringLength is ignored.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_ERROR or SQL_INVALID_HANDLE.
  SQLSetEnvAttr
  sets attributes of environments. 
SQLRETURN  SQLSetEnvAttr(SQLHENV    EnvironmentHandle, 
                         SQLINTEGER Attribute, 
                         SQLPOINTER ValuePtr, 
                         SQLINTEGER StringLength);

Arguments

EnvironmentHandle
EnvironmentHandle must have been allocated by SQLAllocHandle
Attribute
which attribute to set
ValuePtr
Pointer to the value for Attribute. Depending on Attribute, ValuePtr will be a 32-bit integer value or a pointer to a null-terminated string.
StringLength
If ValuePtr points to a character string or a binary buffer, this argument should be the length of *ValuePtr. Otherwise, for ValuePtr of type integer StringLength is ignored.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_ERROR or SQL_INVALID_HANDLE.