SQLite extension module for mapping a CSV file as a read-only SQLite virtual table plus extension function to import a CSV file as a real table. More...
#include <sqlite3ext.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <limits.h>Go to the source code of this file.
Data Structures | |
| struct | csv_file |
| Structure to implement CSV file handle. More... | |
| struct | csv_guess_fmt |
| Info to guess CSV layout. More... | |
| struct | csv_vtab |
| Structure to describe a CSV virtual table. More... | |
| struct | csv_cursor |
| Structure to describe CSV virtual table cursor. More... | |
Typedefs | |
| typedef struct csv_file | csv_file |
| typedef struct csv_guess_fmt | csv_guess_fmt |
| typedef struct csv_vtab | csv_vtab |
Functions | |
| static void | append_free (char **in) |
| Free dynamically allocated string buffer. More... | |
| static char * | append (char **in, char const *append, char quote) |
| Append a string to dynamically allocated string buffer with optional quoting. More... | |
| static char * | unquote (char const *in) |
| Strip off quotes given string. More... | |
| static int | maptype (char const *type) |
| Map string to SQLite data type. More... | |
| static void | conv_names (char **names, int ncols) |
| Convert and collapse white space in column names to underscore. More... | |
| static void | result_or_bind (sqlite3_context *ctx, sqlite3_stmt *stmt, int idx, char *data, int len, int type) |
| Make result data or parameter binding accoring to type. More... | |
| static int | process_col (sqlite3_context *ctx, sqlite3_stmt *stmt, int idx, char *data, int type, int conv) |
| Process one column of the current row. More... | |
| static csv_file * | csv_open (const char *filename, const char *sep, const char *quot) |
| Open CSV file for reading and return handle to it. More... | |
| static void | csv_close (csv_file *csv) |
| Close CSV file handle. More... | |
| static int | csv_eof (csv_file *csv) |
| Test EOF on CSV file handle. More... | |
| static long | csv_seek (csv_file *csv, long pos) |
| Position CSV file handle. More... | |
| static void | csv_rewind (csv_file *csv) |
| Rewind CSV file handle. More... | |
| static long | csv_tell (csv_file *csv) |
| Return current position of CSV file handle. More... | |
| static int | csv_getline (csv_file *csv, csv_guess_fmt *guess) |
| Read and process one line of CSV file handle. More... | |
| static int | csv_ncols (csv_file *csv) |
| Return number of columns of current row in CSV file. More... | |
| static char * | csv_coldata (csv_file *csv, int n) |
| Return nth column of current row in CSV file. More... | |
| static int | csv_guess (csv_file *csv) |
| Guess CSV layout of CSV file handle. More... | |
| static int | csv_vtab_connect (sqlite3 *db, void *aux, int argc, const char *const *argv, sqlite3_vtab **vtabp, char **errp) |
| Connect to virtual table. More... | |
| static int | csv_vtab_create (sqlite3 *db, void *aux, int argc, const char *const *argv, sqlite3_vtab **vtabp, char **errp) |
| Create virtual table. More... | |
| static int | csv_vtab_disconnect (sqlite3_vtab *vtab) |
| Disconnect virtual table. More... | |
| static int | csv_vtab_destroy (sqlite3_vtab *vtab) |
| Destroy virtual table. More... | |
| static int | csv_vtab_bestindex (sqlite3_vtab *vtab, sqlite3_index_info *info) |
| Determines information for filter function according to constraints. More... | |
| static int | csv_vtab_open (sqlite3_vtab *vtab, sqlite3_vtab_cursor **cursorp) |
| Open virtual table and return cursor. More... | |
| static int | csv_vtab_close (sqlite3_vtab_cursor *cursor) |
| Close virtual table cursor. More... | |
| static int | csv_vtab_next (sqlite3_vtab_cursor *cursor) |
| Retrieve next row from virtual table cursor. More... | |
| static int | csv_vtab_filter (sqlite3_vtab_cursor *cursor, int idxNum, const char *idxStr, int argc, sqlite3_value **argv) |
| Filter function for virtual table. More... | |
| static int | csv_vtab_eof (sqlite3_vtab_cursor *cursor) |
| Return end of table state of virtual table cursor. More... | |
| static int | csv_vtab_column (sqlite3_vtab_cursor *cursor, sqlite3_context *ctx, int n) |
| Return column data of virtual table. More... | |
| static int | csv_vtab_rowid (sqlite3_vtab_cursor *cursor, sqlite_int64 *rowidp) |
| Return current rowid of virtual table cursor. More... | |
| static void | csv_import_func (sqlite3_context *ctx, int argc, sqlite3_value **argv) |
| Import CSV file as table into database. More... | |
| static int | csv_vtab_init (sqlite3 *db) |
| Module initializer creating SQLite functions and modules. More... | |
| int | sqlite3_extension_init (sqlite3 *db, char **errmsg, const sqlite3_api_routines *api) |
| Initializer for SQLite extension load mechanism. More... | |
Variables | |
| static const sqlite3_module | csv_vtab_mod |
| SQLite module descriptor. More... | |
SQLite extension module for mapping a CSV file as a read-only SQLite virtual table plus extension function to import a CSV file as a real table.
2012 July 27
The author disclaims copyright to this source code. In place of a legal notice, here is a blessing:
May you do good and not evil. May you find forgiveness for yourself and forgive others. May you share freely, never taking more than you give.
Definition in file csvtable.c.
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Append a string to dynamically allocated string buffer with optional quoting.
| in | input string pointer |
| append | string to append |
| quote | quote character or NUL |
Definition at line 118 of file csvtable.c.
Referenced by csv_import_func(), and csv_vtab_connect().
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Free dynamically allocated string buffer.
| in | input string pointer |
Definition at line 97 of file csvtable.c.
Referenced by csv_import_func(), and csv_vtab_connect().
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Convert and collapse white space in column names to underscore.
| names | string vector of column names |
| ncols | number of columns |
Definition at line 246 of file csvtable.c.
Referenced by csv_import_func(), and csv_vtab_connect().
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Close CSV file handle.
| csv | CSV file handle |
Definition at line 555 of file csvtable.c.
References csv_file::cols, csv_file::f, csv_file::line, csv_file::quot, and csv_file::sep.
Referenced by csv_import_func(), csv_vtab_connect(), and csv_vtab_disconnect().
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Return nth column of current row in CSV file.
| csv | CSV file handle |
| n | column number |
Definition at line 841 of file csvtable.c.
References csv_file::cols.
Referenced by csv_import_func(), and csv_vtab_column().
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Test EOF on CSV file handle.
| csv | CSV file handle |
Definition at line 584 of file csvtable.c.
References csv_file::f.
Referenced by csv_vtab_eof().
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Read and process one line of CSV file handle.
| csv | CSV file handle |
| guess | NULL or buffer for guessing file format |
Definition at line 644 of file csvtable.c.
References csv_file::cols, csv_file::f, csv_guess_fmt::hist, csv_file::isdos, csv_file::line, csv_file::maxc, csv_file::maxl, csv_file::ncols, csv_guess_fmt::nlines, csv_file::quot, and csv_file::sep.
Referenced by csv_guess(), csv_import_func(), csv_vtab_connect(), and csv_vtab_next().
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Guess CSV layout of CSV file handle.
| csv | CSV file handle |
Definition at line 856 of file csvtable.c.
References csv_getline(), csv_rewind(), csv_guess_fmt::hist, min, csv_guess_fmt::nlines, csv_file::pos0, csv_file::quot, and csv_file::sep.
Referenced by csv_import_func(), and csv_vtab_connect().
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Import CSV file as table into database.
| ctx | SQLite function context |
| argc | number of arguments |
| argv | argument vector |
Argument vector contains:
argv[0] - name of table to create (required)
argv[1] - filename (required)
argv[2] - number, when non-zero use first line as column names, when negative use given type names (optional)
argv[3] - number, when non-zero, translate data (optional, see below)
argv[4] - column separator characters (optional)
argv[5] - string quoting characters (optional)
argv[6] - column/type name for first column (optional)
..
argv[X] - column/type name for last column (optional)
Translation flags:
1 - convert ISO-8859-1 to UTF-8
2 - perform backslash substitution
4 - convert and collapse white-space in column names to underscore
10 - convert to single quote, in addition to backslash substitution
Definition at line 1351 of file csvtable.c.
References append(), append_free(), csv_file::cols, conv_names(), csv_close(), csv_coldata(), csv_getline(), csv_guess(), csv_ncols(), csv_open(), csv_rewind(), csv_tell(), maptype(), csv_file::ncols, csv_file::pos0, process_col(), csv_file::quot, and csv_file::sep.
Referenced by csv_vtab_init().
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Return number of columns of current row in CSV file.
| csv | CSV file handle |
Definition at line 825 of file csvtable.c.
References csv_file::cols, and csv_file::ncols.
Referenced by csv_import_func(), and csv_vtab_connect().
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Open CSV file for reading and return handle to it.
| filename | name of CSV file |
| sep | column separator characters or NULL |
| quot | string quote characters or NULL |
Definition at line 496 of file csvtable.c.
References csv_file::cols, csv_file::f, csv_file::isdos, csv_file::line, csv_file::maxc, csv_file::maxl, csv_file::ncols, csv_file::pos0, csv_file::quot, and csv_file::sep.
Referenced by csv_import_func(), and csv_vtab_connect().
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Rewind CSV file handle.
| csv | CSV file handle |
Definition at line 614 of file csvtable.c.
References csv_seek(), csv_file::f, and csv_file::pos0.
Referenced by csv_guess(), csv_import_func(), csv_vtab_connect(), csv_vtab_filter(), and csv_vtab_open().
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Position CSV file handle.
| csv | CSV file handle |
| pos | position to seek |
Definition at line 600 of file csvtable.c.
References csv_file::f.
Referenced by csv_rewind().
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Return current position of CSV file handle.
| csv | CSV file handle |
Definition at line 628 of file csvtable.c.
References csv_file::f.
Referenced by csv_import_func(), csv_vtab_connect(), csv_vtab_next(), and csv_vtab_open().
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Determines information for filter function according to constraints.
| vtab | virtual table |
| info | index/constraint iinformation |
Definition at line 1150 of file csvtable.c.
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Close virtual table cursor.
| cursor | cursor pointer |
Definition at line 1185 of file csvtable.c.
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Return column data of virtual table.
| cursor | virtual table cursor |
| ctx | SQLite function context |
| n | column index |
Definition at line 1253 of file csvtable.c.
References csv_vtab::coltypes, csv_vtab::convert, csv_vtab::csv, csv_coldata(), csv_cursor::cursor, and process_col().
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Connect to virtual table.
| db | SQLite database pointer |
| aux | user specific pointer (unused) |
| argc | argument count |
| argv | argument vector |
| vtabp | pointer receiving virtual table pointer |
| errp | pointer receiving error messag |
Argument vector contains:
argv[0] - module name
argv[1] - database name
argv[2] - table name (virtual table)
argv[3] - filename (required)
argv[4] - number, when non-zero use first line as column names, when negative use given type names (optional)
argv[5] - number, when non-zero, translate data (optional, see below)
argv[6] - column separator characters (optional)
argv[7] - string quoting characters (optional)
argv[8] - column/type name for first column (optional)
..
argv[X] - column/type name for last column (optional)
Translation flags:
1 - convert ISO-8859-1 to UTF-8
2 - perform backslash substitution
4 - convert and collapse white-space in column names to underscore
10 - convert to single quote, in addition to backslash substitution
Definition at line 966 of file csvtable.c.
References append(), append_free(), csv_file::cols, csv_vtab::coltypes, conv_names(), csv_vtab::convert, csv_vtab::csv, csv_close(), csv_getline(), csv_guess(), csv_ncols(), csv_open(), csv_rewind(), csv_tell(), maptype(), csv_file::ncols, csv_file::pos0, csv_file::quot, csv_file::sep, unquote(), and csv_vtab::vtab.
Referenced by csv_vtab_create().
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Create virtual table.
| db | SQLite database pointer |
| aux | user specific pointer (unused) |
| argc | argument count |
| argv | argument vector |
| vtabp | pointer receiving virtual table pointer |
| errp | pointer receiving error messag |
Definition at line 1107 of file csvtable.c.
References csv_vtab_connect().
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Destroy virtual table.
| vtab | virtual table pointer |
Definition at line 1137 of file csvtable.c.
References csv_vtab_disconnect().
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Disconnect virtual table.
| vtab | virtual table pointer |
Definition at line 1121 of file csvtable.c.
References csv_vtab::csv, and csv_close().
Referenced by csv_vtab_destroy().
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Return end of table state of virtual table cursor.
| cursor | virtual table cursor |
Definition at line 1236 of file csvtable.c.
References csv_vtab::csv, csv_eof(), and csv_cursor::cursor.
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Filter function for virtual table.
| cursor | virtual table cursor |
| idxNum | unused (always 0) |
| idxStr | unused |
| argc | number arguments (unused, 0) |
| argv | argument (nothing) |
Definition at line 1219 of file csvtable.c.
References csv_vtab::csv, csv_rewind(), csv_vtab_next(), and csv_cursor::cursor.
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Module initializer creating SQLite functions and modules.
| db | database pointer |
Definition at line 1591 of file csvtable.c.
References csv_import_func(), and csv_vtab_mod.
Referenced by sqlite3_extension_init().
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Retrieve next row from virtual table cursor.
| cursor | virtual table cursor |
Definition at line 1198 of file csvtable.c.
References csv_vtab::csv, csv_getline(), csv_tell(), csv_cursor::cursor, and csv_cursor::pos.
Referenced by csv_vtab_filter().
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Open virtual table and return cursor.
| vtab | virtual table pointer |
| cursorp | pointer receiving cursor pointer |
Definition at line 1163 of file csvtable.c.
References csv_vtab::csv, csv_rewind(), csv_tell(), csv_cursor::cursor, and csv_cursor::pos.
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Return current rowid of virtual table cursor.
| cursor | virtual table cursor |
| rowidp | value buffer to receive current rowid |
Definition at line 1270 of file csvtable.c.
References csv_cursor::pos.
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Map string to SQLite data type.
| type | string to be mapped |
Definition at line 216 of file csvtable.c.
Referenced by csv_import_func(), and csv_vtab_connect().
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Process one column of the current row.
| ctx | SQLite function context or NULL |
| stmt | SQLite statement or NULL |
| idx | parameter index, 1-based |
| data | string data |
| type | SQLite type |
| conv | conversion flags |
Definition at line 360 of file csvtable.c.
References result_or_bind().
Referenced by csv_import_func(), and csv_vtab_column().
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Make result data or parameter binding accoring to type.
| ctx | SQLite function context or NULL |
| stmt | SQLite statement or NULL |
| idx | parameter number, 1-based |
| data | string data |
| len | string length |
| type | SQLite type |
Definition at line 286 of file csvtable.c.
Referenced by process_col().
| int sqlite3_extension_init | ( | sqlite3 * | db, |
| char ** | errmsg, | ||
| const sqlite3_api_routines * | api | ||
| ) |
Initializer for SQLite extension load mechanism.
| db | SQLite database pointer |
| errmsg | pointer receiving error message |
| api | SQLite API routines |
Definition at line 1609 of file csvtable.c.
References csv_vtab_init().
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Strip off quotes given string.
| in | string to be processed |
Definition at line 188 of file csvtable.c.
Referenced by csv_vtab_connect().
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SQLite module descriptor.
Definition at line 1298 of file csvtable.c.
Referenced by csv_vtab_init().