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diff --git a/www/c3ref/table_column_metadata.html b/www/c3ref/table_column_metadata.html new file mode 100644 index 0000000..d641f69 --- /dev/null +++ b/www/c3ref/table_column_metadata.html @@ -0,0 +1,205 @@ +<!DOCTYPE html> +<html><head> +<meta name="viewport" content="width=device-width, initial-scale=1.0"> +<meta http-equiv="content-type" content="text/html; charset=UTF-8"> +<link href="../sqlite.css" rel="stylesheet"> +<title>Extract Metadata About A Column Of A Table</title> +<!-- path=../ --> +</head> +<body> +<div class=nosearch> +<a href="../index.html"> +<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0"> +</a> +<div><!-- IE hack to prevent disappearing logo --></div> +<div class="tagline desktoponly"> +Small. Fast. 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The sqlite3_table_column_metadata() +interface returns SQLITE_OK and fills in the non-NULL pointers in +the final five arguments with appropriate values if the specified +column exists. The sqlite3_table_column_metadata() interface returns +SQLITE_ERROR if the specified column does not exist. +If the column-name parameter to sqlite3_table_column_metadata() is a +NULL pointer, then this routine simply checks for the existence of the +table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it +does not. If the table name parameter T in a call to +sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is +undefined behavior.</p> + +<p>The column is identified by the second, third and fourth parameters to +this function. The second parameter is either the name of the database +(i.e. "main", "temp", or an attached database) containing the specified +table or NULL. If it is NULL, then all attached databases are searched +for the table using the same algorithm used by the database engine to +resolve unqualified table references.</p> + +<p>The third and fourth parameters to this function are the table and column +name of the desired column, respectively.</p> + +<p>Metadata is returned by writing to the memory locations passed as the 5th +and subsequent parameters to this function. Any of these arguments may be +NULL, in which case the corresponding element of metadata is omitted.</p> + +<p><blockquote> +<table border="1"> +<tr><th> Parameter <th> Output<br>Type <th> Description</p> + +<p><tr><td> 5th <td> const char* <td> Data type +<tr><td> 6th <td> const char* <td> Name of default collation sequence +<tr><td> 7th <td> int <td> True if column has a NOT NULL constraint +<tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY +<tr><td> 9th <td> int <td> True if column is <a href="../autoinc.html">AUTOINCREMENT</a> +</table> +</blockquote></p> + +<p>The memory pointed to by the character pointers returned for the +declaration type and collation sequence is valid until the next +call to any SQLite API function.</p> + +<p>If the specified table is actually a view, an <a href="../rescode.html">error code</a> is returned.</p> + +<p>If the specified column is "rowid", "oid" or "_rowid_" and the table +is not a <a href="../withoutrowid.html">WITHOUT ROWID</a> table and an +<a href="../lang_createtable.html#rowid">INTEGER PRIMARY KEY</a> column has been explicitly declared, then the output +parameters are set for the explicitly declared column. If there is no +<a href="../lang_createtable.html#rowid">INTEGER PRIMARY KEY</a> column, then the outputs +for the <a href="../lang_createtable.html#rowid">rowid</a> are set as follows:</p> + +<p><pre> +data type: "INTEGER" +collation sequence: "BINARY" +not null: 0 +primary key: 1 +auto increment: 0 +</pre></p> + +<p>This function causes all database schemas to be read from disk and +parsed, if that has not already been done, and returns an error if +any errors are encountered while loading the schema. +</p><p>See also lists of + <a href="objlist.html">Objects</a>, + <a href="constlist.html">Constants</a>, and + <a href="funclist.html">Functions</a>.</p> + |