2.5 Accessing the database dictionary

With this interface we do not envision the use of Prolog as a database manager. Nevertheless, elementary access to the structure of a database is required, for example to validate a database satisfies the assumptions made by the application.

odbc_current_table(+Connection, -Table)

Return on backtracking the names of all tables in the database identified by the connection.

odbc_current_table(+Connection, ?Table, ?Facet)

Enumerate properties of the tables. Defines facets are:

qualifier(Qualifier)

owner(Owner)

comment(Comment)

These facets are defined by SQLTables()

arity(Arity)

This facet returns the number of columns in a table.

odbc_table_column(+Connection, ?Table, ?Column)

On backtracking, enumerate all columns in all tables.

odbc_table_column(+Connection, ?Table, ?Column, ?Facet)

Provides access to the properties of the table as defined by the ODBC call SQLColumns(). Defined facets are:

table_qualifier(Qualifier)

table_owner(Owner)

table_name(Table)

See odbc_current_table/3.

data_type(DataType)

type_name(TypeName)

precision(Precision)

length(Length)

scale(Scale)

radix(Radix)

nullable(Nullable)

remarks(Remarks)

These facets are defined by SQLColumns()

type(Type)

More prolog-friendly representation of the type properties. See section 2.7.

odbc_type(+Connection, ?TypeSpec, ?Facet)

Query the types supported by the data source. TypeSpec is either an integer type-id, the name of an ODBC SQL type or the constant all_types to enumerate all known types. This predicate calls SQLGetTypeInfo() and its facet names are derived from the specification of this ODBC function:

name(Name)

Name used by the data-source. Use this in CREATE statements

data_type(DataType)

Numeric identifier of the type

precision(Precision)

When available, maximum precision of the type.

literal_prefix(Prefix)

When available, prefix for literal representation.

literal_suffix(Suffix)

When available, suffix for literal representation.

create_params(CreateParams)

When available, arguments needed to create the type.

nullable(Bool)

Whether the type can be NULL. May be unknown

case_sensitive(Bool)

Whether values for this type are case-sensitive.

searchable(Searchable)

Whether the type can be searched. Values are false, true, like_only or all_except_like.

unsigned(Bool)

When available, whether the value is signed. Please note that SWI-Prolog does not provide unsigned integral values.

money(Bool)

Whether the type represents money.

auto_increment(Bool)

When available, whether the type can be auto-incremented.

local_name(LocalName)

Name of the type in local language.

minimum_scale(MinScale)

Minimum scale of the type.

maximum_scale(MaxScale)

Maximum scale of the type.

odbc_table_primary_key(+Connection, +Table, ?Column)

True when Column is a primary key in Table.

odbc_table_foreign_key(+Connection, ?PkTable, ?PkCol, ?FkTable, ?FkCol)

True when PkTable/PkCol FkTable/FkCol is a foreign keys column.