Script to import mysqldump by splitting into individual tables

restore_db.sh

#!/bin/bash

# Name of the gzipped backup file (passed as command-line argument)
if [ -z "$1" ]; then
    echo "Error: Backup file name is required as the first argument."
    echo "Usage: $0 <backup_file.sql.gz>"
    exit 1
fi
backup_file="$1"

# Directory to restore the dump
restore_dir="restore-dump"

# List of tables to exclude (remove insert statements)
excluded_tables=(
    "tabAdditional Salary"
    # Add more table names here, one per line, inside the quotes
    "another_table_to_exclude"
    "yet_another_table"
)

# Create the restore directory if it doesn't exist
if [ ! -d "$restore_dir" ]; then
    mkdir "$restore_dir"
    echo "Created directory: $restore_dir"
fi

# Extract the gzipped backup file into the restore directory
filename=$(basename "$backup_file" .gz) # Extract filename without .gz
if gunzip -c "$backup_file" > "$restore_dir/$filename"; then
    echo "Extracted '$backup_file' to '$restore_dir/$filename'"
else
    echo "Error: Failed to extract '$backup_file'. Exiting."
    exit 1
fi

# Navigate to the restore directory
cd "$restore_dir" || {
    echo "Failed to change directory to '$restore_dir'. Exiting."
    exit 1
fi

# Split the extracted SQL file
csplit -z -f dump_part_ -b "%03d.sql" "$filename" "/^DROP TABLE IF EXISTS/" "{*}"

MAX_FILE_SIZE=$((300 * 1024 * 1024)) # 300MB in bytes

for f in dump_part_*.sql; do
    file_size=$(stat -c "%s" "$f")
    table=$(head -n 1 "$f" | sed -n "s/^DROP TABLE IF EXISTS \`\(.*\)\`;/\1/p")

    echo "Processing file: $f"
    if [ -n "$table" ]; then
        echo "Table name: $table"
    else
        echo "Could not extract table name."
    fi

    skip_import=0 # Initialize skip_import flag

    # Check if the table is in the excluded list
    for excluded_table in "${excluded_tables[@]}"; do
        if [ "$table" = "$excluded_table" ]; then
            echo "Excluding table '$table' from import."
            skip_import=1
            # Remove the insert statement from the file
            sed -i '' "/LOCK TABLES \`$excluded_table\` WRITE;/,/UNLOCK TABLES;/d" "$f"
            echo "Removed insert statements for table '$excluded_table' from file '$f'"
            # Recalculate file size after removing the insert statements
            file_size=$(stat -c "%s" "$f")
            break # Exit the inner loop
        fi
    done

    if (( file_size > MAX_FILE_SIZE )); then
        echo "Skipping '$f' as it exceeds 300MB ($((file_size / (1024 * 1024)))MB)"
        if [ -n "$table" ]; then
            new_filename="${table}.skipped.sql"
            mv "$f" "$new_filename"
            echo "Renamed skipped file '$f' to '$new_filename'"
        else
            echo "Skipped file '$f' was not renamed."
        fi
        continue # Skip to the next file
    fi

    if [ $skip_import -eq 1 ]; then
        echo "Skipping import for '$f' because its table is excluded."
        continue
    fi

    echo "Importing $f ($((file_size / (1024 * 1024)))MB)"
    mysql -u root -pPassword dbname < "$f"
done

script can be used when large .sql.gz create problems
tables to skip insert can be specified
also skipped files greater than specified size are renamed, so they can be imported later